WO2025155225A1

WO2025155225A1 - Indicating available quality of experience (qoe) related information after a mobility operation

Info

Publication number: WO2025155225A1
Application number: PCT/SE2024/051080
Authority: WO
Inventors: Johan Rune; Cecilia EKLÖF; Liping Zhang; Luca LUNARDI; Filip BARAC; Vengatanathan KRISHNAMOORTHI
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2024-01-17
Filing date: 2024-12-13
Publication date: 2025-07-24
Anticipated expiration: 2026-07-17

Abstract

Embodiments include methods for a user equipment (UE) configured to perform quality-of- experience (QoE) measurements in a radio access network (RAN) Such methods include obtaining and storing QoE-related information and subsequently connecting to a first cell served by a first RAN node. Such methods include, while at least a portion of the stored QoE-related information has not been sent to the first RAN node, performing a mobility operation from the first cell to a second cell served by a second RAN node. Such methods include sending, to the second RAN node, an indication of QoE-related information available to be fetched from the UE. Other embodiments include complementary methods for the second RAN node, as well as UEs and RAN nodes configured to perform such methods.

Description

INDICATING AVAILABLE QUALITY OF EXPERIENCE (QOE) RELATED INFORMATION AFTER A MOBILITY OPERATION

TECHNICAL FIELD

The present disclosure generally relates to wireless networks, and more specifically to handling of a quality-of-experience (QoE) reports and configurations stored by a user equipment (UE), after the UE changes serving radio access network (RAN) node during a mobility operation.

BACKGROUND

Currently the fifth generation (5G) of cellular systems is being standardized within the Third-Generation Partnership Project (3GPP). 5G is developed for maximum flexibility to support many different use cases including enhanced mobile broadband (eMBB), machine type communications (MTC), ultra-reliable low latency communications (URLLC), side-link device- to-device (D2D), and several other use cases.

Application-layer quality of experience (QoE) measurements were specified for user equipment (UEs) operating in fourth generation Long Term Evolution (LTE) and third generation UMTS networks, and are being specified in 3GPP for UEs operation in NR networks. Measurements in these networks operate according to common high-level principles, with the purpose of measuring the experience of end users when using certain applications over the network. For example, QoE measurements for streaming services and for MTSI (Mobility Telephony Service for IMS) are supported in LTE.

QoE measurements in 5G will include streaming services as in LTE but will also be needed for other services and use cases such as augmented or virtual reality (AR/VR), URLLC, etc. 5G networks are also expected to use more adaptive QoE management schemes that enable intelligent network optimization.

Similar to LTE, UE QoE measurements made in the 5G radio access network (i.e., NG- RAN) may be initiated by a management function (e.g., OAM) in a generic way for a group of UEs, or they may be initiated by the core network (e.g., 5GC) towards a specific UE based on signaling with the NG-RAN. These two approaches are often referred to as signaling-based (or s-based) QoE and management-based (or m-based) QoE, respectively. For NR QoE in particular, these two approaches are also referred to as signaling-based activation of QoE measurement collection (QMC) and management-based activation of QMC, respectively.

Radio resource control (RRC) signaling is used to configure QoE measurements in UEs and to collect QoE measurement result files from configured UEs. A QMC configuration from a core network (e.g., EPC, 5GC) or a network operations/administration /maintenance (OAM) function is encapsulated in a transparent container and sent to a UE’s serving base station (e.g., eNB, gNB), which forwards it to a UE in an RRC message. QoE measurements made by the UE are encapsulated in a transparent container and sent to the serving base station in an RRC message. The serving base station then forwards the container to a Trace Collector Entity (TCE) or a Measurement Collection Entity (MCE) associated with the CN.

A QMC configuration includes measurement details that are encapsulated in a container that is transparent to the NG-RAN. An NG-RAN node may receive multiple management-based or signaling-based QMC configurations, respectively, from OAM or 5GC.

In addition to conventional or legacy QoE metrics, 3 GPP has agreed to support so-called “RAN-visible” (or RV, for short) QoE metrics and QoE values. RVQoE metrics are a subset of legacy QoE metrics collected from UE and RVQoE values are derived from legacy QoE metrics through a model and/or function. Both are RAN-visible because they can be useful (in some way) to the RAN (e.g., NG-RAN).

Multicast and Broadcast Services (MBS) specified in 3GPP TS 23.247 (vl 8.3.0) is a resource-efficient, point-to-multipoint service in which data is transmitted from a single source (e.g., gNB) to multiple UE recipients. In particular, the same service and content data from a single source can be provided simultaneously to all UEs in a geographical area (via broadcast service) or to a specific group of UEs (in the multicast service). In other words, all UEs in a given area can receive MBS broadcast data while only the targeted group of UEs are authorized to receive MBS multicast. Each UE can receive MBS broadcast service independent of RRC state, while only UEs in RRC CONNECTED can a MBS multicast service. In addition, multicast data can be delivered to a UE via Point-to-Point (PTP) or Point-To-Multipoint (PTM) mechanisms, both of which can utilize UE hybrid ARQ (HARQ) feedback, as specified in 3GPP TS 38.300 (v!7.6.0).

SUMMARY

As part of Rel-18, 3GPP is specifying MBS-related QoE measurements for UEs in RRC INACTIVE and RRC IDLE states, in addition to existing MBS-related QoE measurements for RRC CONNECTED UEs. As such, a UE configured to perform QoE measurements on application sessions carried by MBS in RRC IDLE retains the QMC configuration when transitioning to RRC IDLE. In contrast, a UE releases non-MBS QMC configurations when it transitions from RRC CONNECTED to RRC IDLE. Although the UE’s serving gNB will be aware of this condition, various problems, issues, and/or difficulties can occur when the UE performs a mobility operation after entering RRC_CONNECTED, such as to a target cell served by a different gNB that is not aware of the UE’s retained QMC configuration(s).

An object of embodiments of the present disclosure is to improve configuration and reporting of QoE measurements that are made by UEs in non-connected states (e.g., RRC IDLE), such as by providing, enabling, and/or facilitating solutions to exemplary problems summarized above and described in more detail below.

Some embodiments include methods (e.g., procedures) for a UE configured to perform QoE measurements in a RAN.

These exemplary methods include obtaining and storing QoE-related information, e.g., from the RAN. These exemplary methods also include subsequently connecting to a first cell served by a first RAN node. These exemplary methods also include, while at least a portion of the stored QoE-related information has not been sent to the first RAN node, performing a mobility operation from the first cell to a second cell served by a second RAN node. These exemplary methods also include sending to the second RAN node an indication of QoE-related information available to be fetched from the UE.

In some embodiments, the QoE-related information includes one or more of the following:

• one or more network (NW) QoE measurement collection (QMC) configurations maintained by the RAN to facilitate QoE measurements by the UE; and

• one or more QoE reports based on QoE measurements performed by the UE in accordance with one or more UE QMC configurations.

In some of these embodiments, obtaining the QoE-related information includes the following operations:

• receiving the one or more NW QMC configurations from the RAN while in a connected state with respect to the RAN;

• subsequently transitioning to a non-connected state with respect to the RAN; and

• performing the QoE measurements while in the non-connected state before connecting to the first cell.

In some variants of these embodiments, the QoE measurements are performed for one or more applications carried by a broadcast service received by the UE while operating in the nonconnected state. In some variants of these embodiments, these exemplary methods also include, while connected to the first cell and before the mobility operation, receiving from the first RAN node a message indicating support for reception of QoE-related information stored by the UE while in the non-connected state.

In some embodiments, these exemplary methods also include, while connected to the first cell and before the mobility operation, sending a subset of the QoE-related information to the first RAN node. In other embodiments, these exemplary methods also include selectively discarding a subset of the stored QoE-related information, based on priority information associated with the stored QoE-related information. In some embodiments, the mobility operation is a handover, and the indication of QoE- related information available to be fetched from the UE is sent to the second RAN node in one of the following messages:

• a message that indicates UE completion of handover execution to the second cell;

• a reconfiguration complete message responsive to a reconfiguration message received from the second RAN node; or

• a UE assistance information message.

In other embodiments, performing the mobility operation includes detecting a radio link failure (RLF) in the first cell and reestablishing the UE’s connection with the RAN in the second cell. In such case, the indication of QoE-related information available to be fetched from the UE is sent to the second RAN node in one of the following messages:

• a reestablishment complete message that indicates UE completion of connection reestablishment in the second cell; or

• a reconfiguration complete message responsive to a reconfiguration message received from the second RAN node.

In other embodiments, the non-connected state is RRC INACTIVE and performing the mobility operation includes the following operations:

• sending to the second RAN node a request to resume the UE’s connection with the RAN in the second cell; and

• receiving from the second RAN node a first message indicating that the request to resume the UE’s connection is rejected.

The indication of QoE-related information available to be fetched from the UE is included in a second message sent after receiving the first message.

In some of these embodiments, the first message is an RRCSetup message that also indicates a new connection for the UE will be set up in the second cell, and the second message is a RRCSetupComplete message indicating UE completion of connection setup in the second cell.

In other of these embodiments, the first message is one of the following: an RRCRelease message, or an RRCRelease message that also indicates the UE’s connection with the RAN is released or suspended. Additionally, the second message is sent during or after setup of a new connection for the UE in the second cell.

In some embodiments, the exemplary method also includes the following operations:

• in response to the indication of QoE-related information available to be fetched from the UE, receiving from the second RAN node a request for the QoE-related information available to be fetched from the UE; and • sending the available QoE-related information to the second RAN node in response to the request.

Other embodiments include methods (e.g., procedures) for a second RAN node configured to manage QoE measurements by UEs operating in the RAN. These exemplary methods are generally complementary to the exemplary methods for a UE, summarized above.

These exemplary methods include performing or facilitating a mobility operation for a UE from a first cell served by a first RAN node to a second cell served by the second RAN node. These exemplary methods also include receiving an indication of QoE-related information available to be fetched from the UE. The QoE-related information was obtained and stored by the UE before connected to the first cell, and at least a portion of the stored QoE-related information was not sent by the UE to the first RAN node before the mobility operation. In some embodiments, the indication is received from the UE. In other embodiments, the indication is received from the source RAN node.

In some embodiments, performing or facilitating the mobility operation includes receiving from the UE a request to resume the UE’s connection with the RAN in the second cell, sending to the UE a first message indicating that the request to resume the UE’s connection is rejected. The indication of QoE-related information available to be fetched from the UE is included in a second message received after sending the first message. Various first and second messages are disclosed, including in the above summary of UE embodiments.

In some embodiments, these exemplary methods also include the following operations:

• in response to the indication of QoE-related information available to be fetched from the UE, sending to the UE a request for the QoE-related information available to be fetched from the UE; and

• receiving the available QoE-related information from the UE in response to the request.

Other embodiments include UEs (e.g., wireless devices, etc.) and RAN nodes (e.g, base stations, eNBs, gNBs, ng-eNBs, TRPs, etc.) configured to perform operations corresponding to any of the exemplary methods described herein. Other embodiments include non-transitory, computer-readable media storing program instructions that, when executed by processing circuitry, configure such UEs or RAN nodes to perform operations corresponding to any of the exemplary methods described herein.

These and other embodiments described herein may provide solutions to previously undetected problems or flaws, in 3GPP specifications and agreements, related to treatment of stored QoE-related information when a UE performs a mobility operation (e.g., handover after transition from RRC IDLE to RRC CONNECTED) before being able to send all stored QoE- related information to a serving cell. Embodiments may ensure that a RAN node serving the UE’s target cell (i.e., resulting from the mobility operation) is aware of the stored information, so it can take necessary steps to request it. Since embodiments enable a RAN to collect UE- stored QoE-related information that previously would have been lost, they may improve the availability of QoE measurements in a RAN, which in turn may improve QoE for end users of various services.

These and other objects, features, and advantages of embodiments of the present disclosure will become apparent upon reading the following Detailed Description in view of the Drawings briefly described below.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 shows a high-level view of an exemplary 5G/NR network architecture.

Figure 2 shows exemplary NR user plane (UP) and control plane (CP) protocol stacks.

Figure 3 shows exemplary MBS delivery methods.

Figure 4 shows a signaling flow for activation of management based QoE measurement collection (QMC) in an LTE network.

Figure 5 shows a signaling flow for activation of signaling based QMC in an LTE network, before a UE attaches to the LTE network.

Figure 6 shows an ASN. l data structure for an exemplary AppLayerMeasConfig information element (IE).

Figure 7 shows an ASN. 1 data structure for an exemplary MeasurementReportAppLayer message.

Figure 8 shows an exemplary ASN.1 data structure for an RRCReconflgurationComplete message, according to various embodiments of the present disclosure.

Figure 9 shows an exemplary ASN. 1 data structure for an RRCReestablishmentComplete message, according to various embodiments of the present disclosure

Figure 10 shows a flow diagram of an exemplary method (e.g., procedure) for a UE, according to various embodiments of the present disclosure.

Figure 11 shows a flow diagram of an exemplary method (e.g., procedure) for a second RAN node, according to various embodiments of the present disclosure.

Figure 12 shows a flow diagram of an exemplary method (e.g., procedure) for a first RAN node, according to various embodiments of the present disclosure.

Figure 13 shows a communication system according to various embodiments of the present disclosure.

Figure 14 shows a UE according to various embodiments of the present disclosure. Figure 15 shows a network node according to various embodiments of the present disclosure.

Figure 16 shows a virtualization environment in which some embodiments of the present disclosure may be virtualized.

DETAILED DESCRIPTION

Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided as examples to convey the scope of the subject matter to those skilled in the art.

In general, all terms used herein are to be interpreted according to their ordinary meaning to a person of ordinary skill in the relevant technical field, unless a different meaning is expressly defined and/or implied from the context of use. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise or clearly implied from the context of use. The operations of any methods and/or procedures disclosed herein do not have to be performed in the exact order disclosed, unless an operation is explicitly described as following or preceding another operation and/or where it is implicit that an operation must follow or precede another operation. Any feature of any embodiment disclosed herein can apply to any other disclosed embodiment, as appropriate. Likewise, any advantage of any embodiment described herein can apply to any other disclosed embodiment, as appropriate.

Furthermore, the following terms are used throughout the description given below:

• Radio Access Node: As used herein, a “radio access node” (or equivalently “radio network node,” “radio access network node,” or “RAN node”) can be any node in a radio access network (RAN) that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g, gNB in a 3GPP 5G/NR network or an enhanced or eNB in a 3GPP LTE network), base station distributed components (e.g. CU and DU), a high-power or macro base station, a low-power base station (c.g. micro, pi co, femto, or home base station, or the like), an integrated access backhaul (IAB) node, a transmission point (TP), a transmission reception point (TRP), a remote radio unit (RRU or RRH), and a relay node.

• Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a serving gateway (SGW), aPDN Gateway (P-GW), a Policy and Charging Rules Function (PCRF), an access and mobility management function (AMF), a session management function (SMF), a user plane function (UPF), a Charging Function (CHF), a Policy Control Function (PCF), an Authentication Server Function (AUSF), a location management function (LMF), or the like.

• Wireless Device: As used herein, a “wireless device” (or “WD” for short) is any type of device that is capable, configured, arranged and/or operable to communicate wirelessly with network nodes and/or other wireless devices. Communicating wirelessly can involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. Unless otherwise noted, the term “wireless device” is used interchangeably herein with the term “user equipment” (or “UE” for short), with both of these terms having a different meaning than the term “network node”.

• Radio Node: As used herein, a “radio node” can be either a “radio access node” (or equivalent term) or a “wireless device.”

• Network Node: As used herein, a “network node” is any node that is either part of the radio access network (e.g, a radio access node or equivalent term) or of the core network (e.g., a core network node discussed above) of a cellular communications network. Functionally, a network node is equipment capable, configured, arranged, and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the cellular communications network, to enable and/or provide wireless access to the wireless device, and/or to perform other functions (e.g., administration) in the cellular communications network.

• Node: As used herein, the term “node” (without prefix) can be any type of node that can in or with a wireless network (including RAN and/or core network), including a radio access node (or equivalent term), core network node, or wireless device. However, the term “node” may be limited to a particular type (e.g., radio access node, IAB node) based on its specific characteristics in any given context.

The above definitions are not meant to be exclusive. In other words, various ones of the above terms may be explained and/or described elsewhere in the present disclosure using the same or similar terminology. Nevertheless, to the extent that such other explanations and/or descriptions conflict with the above definitions, the above definitions should control.

Note that the description given herein focuses on a 3GPP cellular communications system and, as such, 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system and can be applied to any communication system that may benefit from them. 3GPP specifications include messages defined by ASN.l data structures (also referred to as “ASN.1 code”). Parameters, information elements (IES), and fields defined in these ASN.1 data structures are often named with suffixes indicating the 3 GPP release that introduced them (e.g. rl7” for a parameter/IE/field introduced in 3GPP Rel-17). For the sake of simplicity, parameters, IEs, and fields defined in these ASN.l data structures may be referred in descriptions without the suffix while retaining the same meaning (e.g., “AppLayerMeasConflg-r 17" and ‘AppLayerMeasConflg” are equivalent).

Figure 1 illustrates a high-level view of an exemplary 5G network architecture, consisting of a Next Generation Radio Access Network (NG-RAN, 199) and a 5G Core (5GC, 198). The NG-RAN can include one or more gNodeB’s (gNBs) connected to the 5GC via one or more NG interfaces, such as gNBs (100, 150) connected via respective interfaces (102, 152). More specifically, the gNBs can be connected to one or more Access and Mobility Management Functions (AMFs) in the 5GC via respective NG-C interfaces and to one or more User Plane Functions (UPFs) in 5GC via respective NG-U interfaces. The 5GC can include various other network functions (NFs), such as Session Management Function(s) (SMF).

Although not shown, in some deployments the 5GC (198) may be replaced by an Evolved Packet Core (EPC), which conventionally has been used together with a Long-Term Evolution (LTE) Evolved UMTS RAN (E-UTRAN). In such deployments, gNBs (e.g., 100, 150) can connect to one or more Mobility Management Entities (MMEs) in the EPC via respective Sl-C interfaces and to one or more Serving Gateways (SGWs) in EPC via respective NG-U interfaces.

In addition, the gNBs can be connected to each other via one or more Xn interfaces, such as Xn interface (140) between gNBs (100, 150). The radio technology for the NG-RAN is often referred to as “New Radio” (NR). With respect to the NR interface to UEs, each of the gNBs can support frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof. Each of the gNBs can serve a geographic coverage area including one or more cells and, in some cases, can also use various directional beams to provide coverage in the respective cells. In general, a DL “beam” is a coverage area of a network-transmitted reference signal (RS) that may be measured or monitored by a UE.

The NG-RAN is layered into a Radio Network Layer (RNL) and a Transport Network Layer (TNL). The NG-RAN logical nodes and interfaces between them is defined as part of the RNL. For each NG-RAN interface (NG, Xn, Fl) the related TNL protocol and the functionality are specified. The TNL provides services for user plane transport and signaling transport.

NG RAN logical nodes (e.g., gNB 100) include a Central Unit (CU or gNB-CU, e.g., 110) and one or more Distributed Units (DU or gNB-DU, e.g., 120, 130). CUs are logical nodes that host higher-layer protocols and perform various gNB functions such controlling the operation of DUs. DUs are decentralized logical nodes that host lower layer protocols and can include, depending on the functional split option, various subsets of the gNB functions. Each CU and DU can include various circuitry needed to perform their respective functions, including processing circuitry, communication interface circuitry (e.g., transceivers), and power supply circuitry.

A gNB-CU connects to one or more gNB-DUs over respective Fl logical interfaces (e.g., 122 and 132 shown in Figure 1). However, each gNB-DU can be connected to only one gNB-CU. The gNB-CU and its connected gNB-DU(s) are only visible to other gNBs and the 5GC as a gNB. In other words, the Fl interface is not visible beyond gNB-CU.

Figure 2 shows an exemplary configuration of NR user plane (UP) and control plane (CP) protocol stacks between a UE (210), a gNB (220), and an AMF (230). Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP) layers between UE and gNB are common to UP and CP. PDCP provides ciphering/deciphering, integrity protection, sequence numbering, reordering, and duplicate detection for both CP and UP, as well as header compression and retransmission for UP data.

On the UP side, Internet protocol (IP) packets arrive to PDCP as service data units (SDUs), and PDCP creates protocol data units (PDUs) to deliver to RLC. The Service Data Adaptation Protocol (SDAP) layer handles quality-of-service (QoS) including mapping between QoS flows and Data Radio Bearers (DRBs) and marking QoS flow identifiers (QFI) in UL and DL packets. RLC transfers PDCP PDUs to MAC through logical channels (LCH). RLC provides error detection/correction, concatenation, segmentation/reassembly, sequence numbering, reordering of data transferred to/from the upper layers. MAC provides mapping between LCHs and PHY transport channels, LCH prioritization, multiplexing into or demultiplexing from transport blocks (TBs), hybrid ARQ (HARQ) error correction, and dynamic scheduling (in gNB). PHY provides transport channel services to MAC and handles transfer over the NR radio interface, e.g., via modulation, coding, antenna mapping, and beam forming.

On the CP side, the non-access stratum (NAS) layer between UE and AMF handles UE/gNB authentication, mobility management, and security control. RRC sits below NAS in the UE but terminates in the gNB rather than the AMF. RRC controls communications between UE and gNB at the radio interface as well as the mobility of a UE between cells in the NG-RAN. RRC also broadcasts system information (SI) and performs establishment, configuration, maintenance, and release of DRBs and Signaling Radio Bearers (SRBs) and used by UEs. Additionally, RRC controls addition, modification, and release of carrier aggregation (CA) and dual-connectivity (DC) configurations for UEs, and performs various security functions such as key management.

After a UE is powered ON it will be in the RRC IDLE until an RRC connection is established with the network, at which time the UE will transition to RRC CONNECTED (e.g, where data transfer can occur). The UE returns to RRC IDLE after the connection with the network is released. In RRC IDLE, the UE’s radio is active on a discontinuous reception (DRX) schedule configured by upper layers. During DRX active periods (also referred to as "‘DRX On durations”), an RRC IDLE UE receives SI broadcast in the cell where the UE is camping, performs measurements of neighbor cells to support cell reselection, and monitors a paging channel on PDCCH for pages from 5GC via gNB. An NR UE in RRC IDLE is not known to the gNB serving the cell where the UE is camping.

NR RRC also includes an RRC INACTIVE state in which a UE is known (e.g., via UE context) by the serving gNB. RRC_INACTIVE has some properties similar to a “suspended” condition used in LTE. More specifically, an RRC INACTIVE UE remains in CM- CONNECTED (i.e., where the UE’s 5GC resources are maintained) and can move within a RAN Notification Area (RNA) configured by NG-RAN without notifying the NG-RAN of changes in serving gNBs within the RNA. In RRC_INACTIVE, the last serving gNB node keeps the UE context and the UE-associated NG connection with the UE’s serving AMF and UPF.

As mentioned above, MBS specified in 3GPP TS 23.247 (v!8.3.0) is a resource-efficient, point-to-multipoint service in which data is transmitted from a single source (e.g., gNB) to multiple UE recipients. In particular, the same service and content data from a single source can be provided simultaneously to all UEs in a geographical area (via broadcast service) or to a specific group of UEs (in the multicast service). In other words, all UEs in a given area can receive MBS broadcast data while only the targeted group of UEs are authorized to receive MBS multicast. Each UE can receive MBS broadcast service independent of RRC state, while only UEs in RRC CONNECTED can a MBS multicast service. In addition, multicast data can be delivered to a UE via Point-to-Point (PTP) or Point-To-Multipoint (PTM) mechanisms, both of which can utilize UE hybrid ARQ (HARQ) feedback, as specified in 3GPP TS 38.300 (v!7.6.0).

Figure 3 illustrates exemplary MBS delivery methods as further specified 3GPP TS 23.247 (vl 8.3.0). Between 5GC and NG-RAN, there are two possible delivery methods to transmit the MBS data:

• 5GC Individual MBS traffic delivery, which is only applied for multicast MBS sessions. 5GC receives a single copy of MBS data packets and delivers separate copies of those MBS data packets to individual UEs via per-UE PDU sessions, hence for each such UE one PDU session is required to be associated with a Multicast MBS session. The MBS data received by the MB-UPF is replicated towards the UPF(s) where individual delivery is performed via unicast transport over N19mb interface.

• 5GC Shared MBS traffic delivery (mandatory), which may be applied for both broadcast and multicast MBS sessions. 5GC receives a single copy of MBS data packets and delivers a single copy of those MBS packets to an NG-RAN node, which then delivers the packets to one or multiple UEs. These incoming MBS traffic packets are delivered from MB-UPF to NG-RAN node via the N3mb interface. This traffic delivery method is required to enable mobility when there is an NG-RAN deployment with non-homogeneous support of MBS. For PTP delivery from NG-RAN to UEs, the NG-RAN delivers separate copies of MBS data packets over NR radio interface to individual UE(s). For PTM delivery from NG-RAN to UEs, the NG-RAN delivers a single copy of MBS data packets over NR radio interface to multiple UEs. However, the NG-RAN may use a combination of PTP/PTM to deliver an MBS data packets to UEs.

An MBS Session Resource may be associated with one or more MBS QoS flows, and each of those flows is associated with a QoS profile. A gNB provides one or more multicast MBS Radio Bearer (MRB) configurations to a UE via RRC signaling, as described in 3GPP TS 38.300 (vl7.6.0) section 16.10.3. For a multicast session, the gNB may change the MRB type via RRC signaling. For a broadcast session, gNB provides a broadcast MRB with one DL-only RLC-UM entity for PTM transmission. In other words, only one type of MRB is specified at any given time for broadcast transmission. Network and protocol architectures are described in detail in 3GPP TS 38.300 (v!7.6.0) sections 16.10.2 and 16.10.3.

Group scheduling mechanisms for MBS delivery are described in 3GPP TS 38.300 (vl7.6.0) clause 16.10.4. Group transmissions use group (G) radio network temporary identifiers (RNTIs), such that a UE can receive different services using the same or different G-RNTIs or G-CS-RNTIs. NG-RAN manages MBS QoS flows, delivers MBS data packets from 5GC to multiple UEs via PTP or PTM (including switching between per UE), and configures UEs for MBS QoS flow reception at application stratum (AS). The NG-RAN also provides multicast session service continuity during UE handovers via Xn and NG interfaces, and provides group paging at multicast session activation toward UEs in CM-IDLE state or CM-CONNECTED with RRC INACTIVE state.

To ensure service continuity of MBS broadcast, a UE in RRC CONNECTED may send an MBS interest indication to its serving gNB. This indication includes the following information:

• List of MBS frequencies UE is interested in receiving, sorted in decreasing order of interest;

• Priority between the reception of all listed MBS frequencies and the reception of any unicast bearer;

• List of MBS broadcast services the UE is interested in receiving, in case SIB20 is scheduled by the UE's PCell; and • UE’s priority to MBS broadcast versus unicast reception

MBS Interest Indication information reporting can be enabled (disabled) by presence (absence) of SI block 21 (SIB21) in cell broadcast.

Mobility support for service continuation for a UE in an MBS session depends on whether broadcast or multicast is being used, and on whether the source and target RAN nodes support MBS. For a multicast MBS session, the following three cases are possible:

1. handover from an NG-RAN node supporting MBS to a node not supporting MBS,

2. handover from an NG-RAN node not supporting MBS to a node supporting MBS, and

3. handover from a node supporting MBS to another node supporting MBS.

In the first two cases above, 5GC Shared MBS Traffic Delivery and 5GC Individual Traffic delivery mechanisms can co-exist temporarily upon handover. Mapping information about unicast QoS flows for multicast data transmission and information about associated multicast QoS flows are provided to an RAN node. The delivery method is switched from 5GC Shared MBS Traffic delivery to 5GC Individual MBS delivery via establishing the N3 tunnel of the PDU Session for Individual delivery. SMF realizes that the target node does not support MBS, and activates a GTP tunnel between UPF and MB-UPF for 5GC Individual MBS traffic delivery.

In the third case above, if the shared delivery for the MBS session has not been established towards the target RAN node, it uses MB-SMF (Multicast Broadcast Session Management Function) and MB-UPF (Multicast Broadcast User Place Function) to establish the Shared delivery for the MBS session. The UE’s PDU sessions - including one associated with the MBS Multicast session and used for the 5GC Individual MBS traffic delivery - are handed over to the target RAN node. SMF triggers the mode switch from individual to shared delivery mode, and the target RAN node establishes shared delivery for the UE’s MBS session upon receiving the MBS Session Context. Finally, 5GC individual MBS traffic delivery is terminated by 5GC and changed to the 5GC shared MBS traffic delivery.

In the Broadcast MBS case, a UE may receive the same service in the target RAN node (which supports MBS) if the same MBS session is established with the 5GC Shared MBS traffic delivery. Currently, the case of the UE being handed over to a node not supporting the MBS within the broadcast area has not been specified.

As briefly mentioned above, application-layer QoE measurements were specified for user equipment (UEs) operating in LTE and UMTS networks, and are being specified in 3GPP for UEs operating in NR networks. Measurements in these networks operate according to common high- level principles, with the purpose of measuring the experience of end users when using certain applications over the network. For example, QoE measurements for streaming services and for MTSI (Mobility Telephony Service for IMS) are supported in LTE. QoE measurements in 5G will include streaming services as in LTE but will also be needed for other services and use cases such as augmented or virtual reality (AR/VR), URLLC, etc. 5G networks are also expected to use more adaptive QoE management schemes that enable intelligent network optimization.

RRC signaling is used to configure QoE measurements in UEs and to collect QoE measurement result files from configured UEs. A QMC configuration from a core network (e.g., EPC, 5GC) or a network OAM function is encapsulated in a transparent container and sent to a UE’s serving base station (e.g., eNB, gNB), which forwards it to a UE in an RRC message. QoE measurements made by the UE are encapsulated in a transparent container and sent to the serving base station in an RRC message. The serving base station then forwards the container to a Trace Collector Entity (TCE) or a Measurement Collection Entity (MCE) associated with the CN.

With m-based QoE, the OAM system is typically interested in general QoE statistics from a certain area, which is configured as an “area scope”. The m-based QoE configuration is sent directly from the OAM system to the RAN nodes controlling cells within the area scope. Each RAN node then selects UEs that are within the area scope and that fulfill any other relevant conditions (e.g., support for relevant application/service type) and sends the m-based QoE configuration to these UEs.

With s-based QoE, the OAM system is interested in collecting QoE measurement results from a specific UE, such as when the user of the UE has filed a service complaint. The OAM system sends the s-based QoE configuration to the HSS (in EPS/LTE) or UDM (in 5GS/NR), which forwards the QoE configuration to the UE’s current mobility management node, e.g., MME in EPS/LTE or AMF in 5G/NR. This CN node then forwards the s-based QoE configuration to the RAN node that serves the concerned UE, and the RAN node forwards it to the UE.

In either case, the UE receives service type indication and the container with the measurement instructions. The UE is not aware of whether a received QoE configuration is m- based or s-based. In legacy systems, the QoE framework is integrated with the Trace functionality and a Trace ID is associated with each QoE configuration. In NR, the QoE functionality will be logically separated from the Trace functionality, but it will still partly reuse the Trace signaling mechanisms.

In NR and LTE, a globally unique QoE reference will be associated with each QoE configuration, with this reference formed by MCC+MNC+QMC ID, where MCC is mobile country code, MNC is mobile network code, and QMC ID is a string of 24 bits. The QoE reference is included in the container with measurement instructions sent to the RAN. For the communication between the gNB and the UE, the QoE reference is replaced by a shorter identifier denoted as measConflgAppLayerld, where there is a one-to-one mapping between a measConflgAppLayerld and a QoE reference for each QoE configuration provided to a UE. The measConflgAppLayerld is stored in the UE AS (or access layer) and forwarded to the UE’s application layer in an AT Command together with the service type indication and the container with the measurement instructions.

QoE reports with collected QoE measurement results are sent from the UE application layer to the UE AS, which forwards them to the RAN, which forwards them to the MCE. These QoE measurement results are placed in a “container” that is uninterpretable by the UE AS and RAN. QoE reporting can be configured to be periodic or only sent at the end of an application session. Furthermore, the RAN can instruct the UE to pause QoE reporting, e.g., in case the cell/gNB is in a state of overload.

The RAN is not aware of when an application session with an associated QoE measurement session is ongoing, nor is the UE AS necessarily aware of this condition. To address this, session start/stop indications can be from the UE application layer to UE AS and from UE AS to the RAN. A session stop indication may be implicit in the form of a QoE report sent when the application session and the associated QoE measurement session are concluded. Also, the RAN may decide to release a QoE configuration in a UE at any time, on an implementationspecific basis. For example, this may be done when the UE has moved outside the area scope for the QoE measurements.

Conventionally, UEs have been able to perform configured QoE measurements for an entire application session, even during a handover. In some circumstances, the UE may also continue QoE measurements until the application session ends, even if the UE earlier moved out of the configured area scope.

As an illustrative example, Figure 4 shows a signal flow of activation of m-based QoE measurement collection (QMC) and reporting of collected information in an LTE network. This signal flow is between a measurement collection entity (MCE, 450), a network manager (NM, 440), a domain manager (DM/EM, 430), one or more eNBs (420) in E-UTRAN, and the UE (410) - particularly access stratum (or access, for short) and application parts of the UE. The following description omits these reference numbers for brevity. Although the operations shown in Figure 4 are given numerical labels, these labels are intended to facilitate the following description rather than to require and/or imply a particular order of the operations.

In operation 1, the NM sends an Activate Area QMC Job message to the DM, which forwards the message to the eNB in operation 2. The message includes a service type (e.g., streaming), a QMC configuration file for the QoE measurements to be performed, a QoE reference identifier, and an area scope for the QMC. According to 3GPP TS 28.405 (vl6.1.0) section 5.2, the QoE reference is globally unique and consists of MCC+MNC+QMC ID, where Mobile Country Code (MCC) and Mobile Network Code (MNC) identify the Public Land Mobile Network (PLMN) containing the NM. QMC ID is a three-octet string generated by the NM or the operator, and identifies the particular QMC job in the traffic nodes and the MCE.

In operation 3, the eNB identifies served cells matching the area scope, as well as UEs in these served cells that match other parameters in the message (e.g., service type). The eNB can base this determination on UE capability information sent from the UE to the eNB (not shown). In operation 4, after identifying the UE matching the received criteria, the eNB sends an RRCConnectionReconflguration message to the AS (e.g., RRC layer) of the UE. The eNB includes the service type, the area scope (e.g., one or more cells, tracking areas, etc.), the QMC configuration file, and the QoE reference.

In operation 5, the UE AS forwards this information to the UE application part using an AT command +CAPPLEVMC, as specified in 3GPP TS 27.007. In general, AT commands can be used to transfer information between different layers in the UE, such as between application and AS. In particular, AT command +CAPPLEVMC is of the following form when used for QoE measurement configuration:

+CAPPLEVMC: <app-meas_service_type>,<start-stop_reporting>[,<app- meas_config_file_length>,<app-meas_config-file>], where the various fields are defined below:

<n>: integer type. Disable and enable presentation of the unsolicited result code +CAPPLEVMC to the TE.

0 Disable presentation of the unsolicited result code

1 Enable presentation of the unsolicited result code <app-meas_service_type>: integer type. Contains the indication of what application that is target for the application level measurement configuration.

1 QoE measurement collection for streaming services

2 QoE measurement collection for MTSI services <start-stop_reporting>: integer type. Indicates the start and stop of the application level measurement reporting for the application indicated by the <app-meas_service_type>.

0 start the application level measurement reporting

1 stop the application level measurement reporting

<app-meas_config_file_length>: integer type. Indicates the number of octets of the <app- meas_config-file> parameter.

<app-meas_config-file>: string of octets. Contains the application level measurement configuration file for the application indicated by the <app-meas_service_type>. The parameter shall not be subject to conventional character conversion as per +CSCS.

In operation 6, the UE starts an application associated with the service type and initiates QMC according to the received configuration and area. The UE assigns this QMC a recording session ID and reports this ID (in operation 7) to the UE AS using the same AT command. In operation 8, the UE AS sends this ID to the eNB in a MeasReportAppLayer RRC message, and the eNB notifies the NM of the initiation of QMC in operation 9.

The UE application layer completes the QMC according to the received configuration (operation 10) and reports the results to the UE AS via AT command +CAPPLEVMR (operation 11) along with the associated QoE reference received earlier. The report can be a transparent container, as discussed earlier. AT command +CAPPLEVMC is of the following form when used for QoE measurement reporting:

+CAPPLEVMC=<app-meas_service_type>,<app-meas_report_length>,<app-meas_report> where the various fields are defined below:

<app_meas_service_type>: integer type. Contains the indication of what application that is providing the application level measurement report.

1 QoE measurement collection for streaming services

2 QoE measurement collection for MTSI services

<app-meas_report_length>: integer type. Indicates the number of octets of the <app- meas_report> parameter.

<app-meas_report>: string of octets. Contains the application level measurement configuration file for the application indicated by the <app-meas_service_type>. The parameter shall not be subject to conventional character conversion as per +CSCS.

In operation 12, the UE AS sends the report and the QoE reference ID to the eNB in a MeasReportAppLayer RRC message. The eNB subsequently forwards the report to the MCE (operation 13). In some cases, the MCE may forward the QoE measurement report another entity in the network for analysis and further action (e.g., in the 0AM system). As another illustrative example, Figure 5 shows a signal flow of activation of s-based QMC for a specific UE before the UE attaches to an LTE network. This signal flow is between a measurement collection entity (MCE, 550), a network manager (EMS, 540), a home subscriber server (HSS, 530), a mobility management entity (MME, 535), one or more eNBs (520) in E- UTRAN, and the UE (510) - particularly access stratum (or access, for short) and application parts of the UE. The following description omits these reference numbers for brevity. Although the operations shown in Figure 5 are given numerical labels, these labels are intended to facilitate the following description rather than to require and/or imply a particular order of the operations.

In operations Oa-b, the UE sends an attach request to its serving eNB, which forwards the attach request to the MME. In operation 0c, the MME sends an Update Location Request to the HSS to update the UE’s location information.

In operation la, the EMS sends an Activate Area QMC Job message to the HSS. The message includes a service type (e.g., streaming), a QMC configuration file for the QoE measurements to be performed, a QoE reference identifier, and an identifier of the UE from which measurements are requested. In general, the contents of the Activate Area QMC Job message are the same as the corresponding message in Figure 4, except for exclusion of the area scope and inclusion of the UE identifier.

In operation lb, the HSS sends an Update Location Response to the MME (i.e., in response to the Update Location Request) and includes the contents of the message received in operation la. The MME forwards the message to the eNB in operation 2. In operation 3, the eNB determines whether the UE’s capabilities match the criteria and/or parameters for QMC that were included in the message of operation 2. The eNB can base this determination on UE capability information sent from the UE to the eNB (not shown).

If the UE’s capabilities are sufficient for the requested QMC, the eNB sends an RRCConnectionReconflguration message to the AS (e.g., RRC layer) of the UE in operation 4. The eNB includes the service type, the area scope (e.g., one or more cells, tracking areas, etc.), the QMC configuration file, and the QoE reference. Operations 5-13 proceed in the same manner as corresponding operations in Figure 4.

A QMC can include various conventional QoE metrics to be reported by the UE, including one or more of the following:

• List of representation switch events, which specify changes in the encoding played back on the UE as a time series;

• Average throughput, as observed by the application client during the measurement interval; • Initial playout delay, which is the time (milliseconds) between when the first media segment is fetched from the application server and when media is retrieved from the client buffer;

• Buffer level, which is a list of buffer occupancy level measurements during playout at normal speed;

• Playlist, which is a sequence of events on the client’s media player (user-triggered and otherwise) that correspond to a sequence of playback events (e.g., playback, representation switch, rebuffering, etc.).

• MPD information, which specifies dynamic adaptive streaming over HTTP (DASH) video representations and their time characteristics;

• Playout delay for media startup, which is the initial delay encountered by the UE between requesting commencement of playback and when playback is commenced; and

• Device information, e.g., physical characteristics of the device such as screen size.

Among the above-listed conventional QoE metrics, the following are specified for 3GPP DASH clients in 3GPP TS 26.247 (vl7.1.0): List of Representation Switch Events, Average Throughput, Initial Playout Delay, Buffer Level, Playlist, MPD Information, and Device information.

NR Rel-16 includes a study on NR QoE management and optimizations for diverse services, with a purpose to study solutions for QoE measurements in NR, not only for streaming services as in LTE but also for other services such as augmented or virtual reality (AR/VR), URLLC, etc. Based on requirements of the various services, the NR study will also include more adaptive QoE management schemes that enable intelligent network optimization to satisfy user experience for diverse services.

Conventionally, QoE measurement reports were intended for OAM system or other entities outside of RAN and CN, and these reports were forwarded transparently by the RAN to an MCE or similar entity. Even so, the RAN could also benefit from receiving measurement results collected at the application layer, e.g. as a complement to the measurements collected by the UE AS (e.g., RRM measurements such as RSRP, RSRQ, SINR, etc.). For instance, the RAN could use application-layer measurement results for real-time (or near-real-time) adaptations of ongoing UE application session, such as by adjusting scheduling priorities.

Accordingly, 3GPP Rel-17 introduced so-called “RAN-visible” (or RV, for short) QoE metrics and QoE values. For example, RVQoE measurements are supported for DASH streaming and virtual reality (VR) services. In general, RVQoE metrics are a subset of legacy QoE metrics collected from UE and RVQoE values are derived from legacy QoE metrics through a model and/or function. Both types are RAN-visible because they are useful (in some way) to the NG- RAN. A general description of RVQoE measurements and related procedures is given in 3GPP TS 38.300 (vl7.60) section 21.4.

Among the conventional QoE metrics mentioned above, Initial Play out Delay and Buffer Level are also specified as RVQoE metrics. These metrics are defined in 3GPP TS 26.247 (vl7.4.1) and ISO/IEC 23009-1, and are specified in 3GPP TS 38.331 (vl7.6.0) as fields AppLayerBufferLevel-r 17 and playoutDelayFor MediaStar tup-r 17 respectively. In addition to these two RVQoE metrics, a MeasurementReportAppLayer message may contain a PDU session ID list (in the form of the pdu-SessionldList-r 17 field) in the RAN-VisibleMeasurements-r 17 IE.

In addition to QoE metrics for DASH streaming discussed above, 3GPP TS 26.346 (v!7.3.0) also defines QoE metrics for LTE MBMS, including the metrics in the table below.

As discussed above, NR UE QoE measurements are configured by an NG-RAN node sending the UE an RRCReconflguration message that includes an AppLayerMeasConflg IE, which carries the QMC. Figure 6 shows an ASN.l data structure for an exemplary AppLayerMeasConflg IE defined in 3GPP TS 38.331 (vl 7.6.0), including agreed-upon changes specified in 3GPP document R2-2314024. The configuration for conventional QoE measurements is contained in the measConflgAppLayerContainer IE, which includes an octet string (XML format) that is readable by the UE application layer. The configuration for RVQoE measurements is contained in the RAN-VisibleParameters IE, which includes a reporting periodicity, a number of buffer level entries to report, and a Boolean (T/F) indicator of whether to report initial playout delay. The following table defines the fields in Figure 6 in more detail.

Subsequently, the UE performs the configured QoE measurements and sends a MeasReportAppLayer RRC message to the gNB, including a QoE measurement result file. Figure 7 shows an ASN.l data structure for an exemplary MeasurementReportAppLayer message. The following table defines the fields in Figure 7 in more detail.

As mentioned above, AT commands can be used to transfer information between application layer and AS in the UE, as further defined in 3GPP TS 27.007 (vl 8.4.0). For NR QoE In particular, AT command +CAPPLEVMCNR is used for sending a QoE configuration (and/or an RVQoE configuration) from AS to application layer in an NR UE, and is further defined in 3GPP TS 27.007 (vl8.4.0) Table 8.84-1 and accompanying text. Likewise, AT command +CAPPLEVMRNR is used for sending QoE reports (and/or RVQoE reports) from application layer to AS in an NR UE, and is further defined in 3GPP TS 27.007 (vl8.4.0) Table 8.85-1 and accompanying text. For simplicity, these commands may be referred to without their “NR” suffixes, making them non- AS specific.

As part of Rel-18, 3GPP is specifying MBS-related QoE measurements for UEs in RRC INACTIVE and RRC IDLEs, in addition to existing MBS-related QoE measurements for RRC CONNECTED UEs. In the context of QoE, MBS is considered a communication service carrying application sessions of various service types, rather than a service type itself. As such, a UE configured to perform QoE measurements on application sessions carried by MBS in RRC IDLE retains its QMC configuration when transitioning to RRC IDLE. In contrast, a UE releases non-MBS QMC configurations when it transitions from RRC CONNECTED to RRC IDLE.

Since the RAN deletes (or releases) all of its stored UE context (i.e., configuration and state information related to the UE) when the UE transitions from RRC CONNECTED to RRC IDLE, the UE’s QoE configuration parameters must be re-instated in the RAN when the UE transitions from RRC IDLE back to RRC CONNECTED. 3GPP has chosen a UE-based solution in which the RAN sends the QoE configuration parameters its maintains (called “network instance of QoE configuration” or “NW QoE configuration”) to the UE while the UE is in RRC CONNECTED, and the UE stores them when transitioning to RRC IDLE. When the UE returns to RRC_CONNECTED, it sends these stored QoE configuration parameters to the RAN, specifically to the gNB serving the cell in which the UE returned to RRC CONNECTED. In this manner, the RAN’s QoE-related context is restored.

When the UE transitions from RRC IDLE to RRC CONNECTED, it indicates availability of any stored QoE reports (i.e., generated while in RRC IDLE) and any stored NW QoE configurations. The UE includes this indication in an RRCSetupComplete (or RRCResumeComplete) message sent at the end of transition from RRC_IDLE (or RRC INACTIVE) to RRC CONNECTED. In particular, the indication is a field named measConflgReportAppLayerAvailable-rl8 having an ASN.1 ENUMERATED type with value of “true” when the UE indicates availability of the stored information. Upon receiving this indication, the gNB may retrieve the QoE report(s) and/or NW QoE configuration(s) by establishing signaling radio bearer 4 (SRB4), which triggers the UE to send the stored information to the gNB on SRB4.

Although the UE’s serving RAN node will be aware of this condition, various problems, issues, and/or difficulties can occur when the UE performs a mobility operation after entering RRC_CONNECTED, such as to a target cell served by a different RAN node that is not aware of the UE’s retained QMC configuration(s). For example, the UE may be handed over from the cell in which it re-entered RRC_CONNECTED (“source cell”) to a target cell served by a target RAN node, before the UE sends the indicated QoE report(s) and/or NW QoE configuration(s), to the serving RAN node. Being unaware of the available information, the target RAN node does not establish SRB4 to trigger the UE to send it, unless the target RAN node has other QoE configuration it wants to send to the UE.

While this is a problem in inter-RAN node handovers, it may also be a problem for intra- RAN node handovers depending on the RAN node implementation. For example, the RAN node’s functionality responsible for the target cell may or may not be aware of the RAN node’s functionality responsible for the source/serving cell.

A similar problem can occur when the UE detects radio link failure (RLF) in the serving cell before the UE sends all the indicated data. If the UE then re-establishes its RRC connection in the target cell controlled by a different RAN node than controls the cell where RLF was detected, then this target RAN node will be unaware of the available information and will not trigger SRB4 establishment. As such, the UE will be unable to send the remainer of its stored QoE reports and/or NW QoE configurations to the target RAN node.

A similar problem can occur when the UE releases to RRC INACTIVE in the serving cell before the UE sends all the indicated data. In such case, the RAN node providing the UE’s serving cell deletes the stored context for the UE, including any NW QoE configurations previously sent to the UE. When the UE attempts resume towards the same RAN node, this results in the setup of a new RRC connection. Having previously deleted the UE context, the RAN node is unaware of the relevant information stored at the UE.

A similar problem can occur when the UE attempts resume from RRC INACTIVE in a target cell served by a different RAN node. In this case, the retrieval of the UE context attempted by the target RAN node towards the previous serving (“anchor”) RAN node fails, such that the target RAN node must set up a new RRC connection for the UE. Embodiments of the present disclosure address these and related problems, issues, and/or difficulties by flexible and efficient techniques that reliably inform a target RAN node that a UE, which recently performed a mobility operation to a target cell served by the target RAN node, has stored QoE reports and/or NW QoE configurations that are available to be fetched. Some embodiments include network-based solutions and while other embodiments include UE-based solutions.

In this manner, embodiments may provide solutions to previously undetected problems or flaws, in 3GPP specifications and agreements, related to treatment of stored QoE reports and/or NW QoE configurations when a UE performs a mobility operation (e.g., handover after transition from RRC IDLE to RRC CONNECTED) before being able to send all stored QoE reports and/or NW QoE configurations to a serving cell. Embodiments may ensure that a RAN node serving the UE’s target cell (i.e., resulting from the mobility operation) is aware of the stored information, so it can take necessary steps to request it. Since embodiments allow a RAN to collect UE-stored QoE-related information that previously would have been lost, they may improve the availability of QoE measurements in a RAN.

In the following description of various embodiments, the following groups of terms and/or abbreviations have the same or substantially similar meanings and, as such, are used interchangeably and/or synonymously unless specifically noted or unless a different meaning is clear from a specific context of use:

• “application layer” and “UE application layer” (RAN nodes generally do not have an application layer);

• “application-layer measurement”, "application measurement”, and “QoE measurement”;

• “conventional QoE measurement”, “legacy QoE measurement”, and “non-RAN-visible QoE measurement”;

• “QoE measurement report” and “QoE report”;

• “RVQoE measurement report” and “RVQoE report”;

• “QoE measurement configuration”, “QoE configuration”, “QMC configuration”;

• “network” and “NW”;

• “available” and “unfetched”;

• “modem”, “radio layer”, “radio network layer”, “access stratum”, and “AS”;

• “radio layer connection” and “RRC connection”;

• “legacy QoE” and “conventional QoE”;

• “UE RRC configuration”, “RRC configuration”, “UE RRC context”, “RRC context”, “context”; • “service” and “application”;

• “measurement collection entity”, “MCE”, “trace collection entity”, and “TCE”.

Embodiments will now be described in more detail. In the following description, “QoE- related information” refers to any combination of QoE reports and NW QoE configurations stored by a UE for subsequent sending to the RAN. Likewise, “source RAN node” and “source cell” refer to the RAN node and the cell in which the UE with available QoE-related information initiated a mobility operation, while “target RAN node” and “target cell” refer to the RAN node and the cell in which the UE with available QoE-related information finished a mobility operation.

In the following description, “NW QoE configuration” and “UE QoE configuration” refer to RAN and UE versions, respectively, of the same QoE configuration. Likewise, “QoE report” may refer to one of the following, depending on the particular context of use:

• content of a measReportAppLayerContainer IE in a MeasurementReportAppLayer RRC message;

• a MeasurementReportAppLayer RRC message;

• MeasReportAppLayer IE in a MeasurementReportAppLayer RRC message; or

• content of the MeasReportAppLayer IE, excluding the ran-VisibleMeasurements IE, in a MeasurementReportAppLayer RRC message.

Similarly, “RVQoE report” refers to the content of a RAN-VisibleMeasurements IE in a MeasurementReportAppLayer RRC message.

In a first set of embodiments (also referred to as “network-based solution”), the source RAN node controlling the source cell informs the target RAN node controlling the target cell that the UE has available stored QoE-related information. For example, the UE previously indicated this availability by setting measConflgReportAppLayerAvailable-rl8 to “true” in an RRCSetupComplete message sent to the source RAN node after transitioning from RRC_IDLE to RRC CONNECTED.

When the mobility operation that follows the UE’s transition from RRC IDLE to RRC_CONNECTED is a handover, the source RAN node informs the target RAN node during the handover preparation, such as by including a new parameter in the appropriate handover request message (e g., HANDOVER REQUEST XnAP message, HANDOVER REQUIRED or HANDOVER REQUEST NGAP message).. The new parameter may be called “ Unfetched QoE- related information” and it could for example be included at the top level of the “UE Application Layer Measurement Configuration Information” IE, or at the top level of the “QMC Configuration Information” IE.

For an Xn-based handover, whether the indication is placed in the top level of the UE Application Layer Measurement Configuration Information IE or at the top level of the QMC Configuration Information IE depends on how the UE has indicated to the source RAN node the existence of stored QoE-related information. If the UE has indicated to the source RAN node only that unfetched QoE-related information is available (i.e., exists), then such an indication from source RAN node to target RAN node can be placed in the top level of the QMC Configuration Information IE. On the other hand, if the UE has indicated availability of specific QoE-related information (e.g., NW QoE configurations), then the indication can be placed in the corresponding (e.g., configuration-specific) UE Application Layer Measurement Configuration Information IE.

In various embodiments, the UE may indicate the presence of unfetched QoE-related information with different levels of detail. For example, the UE may simply indicate that unfetched QoE-related information is available, without indicating what type of information (e.g., NW QoE configurations, QoE reports, or both) is available. As another example, the UE may indicate specific type(s) of QoE-related information available (e.g., NW QoE configurations, QoE reports, or both).

For an NG-based handover, the indication can be included in a HANDOVER REQUIRED or a HANDOVER REQUEST NGAP message, such as in the "QMC Configuration Information’" IE that is included in the "Source NG-RAN Node to Target NG-RAN Node Transparent Container” IE in the “Source to Target Transparent Container” IE. The same considerations regarding the placement of the indication at the top level of the UE Application Layer Measurement Configuration Information IE or at the top level of the QMC Configuration Information IE, as described for the case of Xn-based handover, apply equally to NG-based handover.

Alternatively, the indication of unfetched QoE-related information stored in the UE could be included in the HandoverPreparationlnformation inter-node RRC message, which currently includes RRC context information. For an Xn-based handover, this message is sent from the source RAN node to the target RAN node in the “RRC Context” IE in the HANDOVER REQUEST XnAP message. For an NG-based handover, this message is in the “RRC Container” IE in the “Source NG-RAN Node to Target NG-RAN Node Transparent Container” in the “Source to Target Transparent Container” IE in the HANDOVER REQUIRED or HANDOVER REQUEST NGAP message.

When the mobility operation that follows the transition from RRC IDLE to RRC CONNECTED is detection of RLF followed by RRC re-establishment, the source RAN node informs the target RAN node using a new parameter in the RETRIEVE UE CONTEXT RESPONSE XnAP message, which is used to transfer UE context information from the UE’s previous serving RAN node to the UE’s new serving RAN node during the RRC re-establishment procedure. In this case, the new parameter may be called “Unfetched QoE-related information” and may be included in the UE Application Layer Measurement Configuration Information IE in the QMC Configuration Information IE. The considerations regarding placement of the indication at the top level of the UE Application Layer Measurement Configuration Information IE or at the top level of the QMC Configuration Information IE, described above for handover, apply equally to the mobility operation of RLF followed by RRC re-establishment.

In other embodiments, the indication from the source RAN node to the target RAN node may be a request (or indication) to setup SRB4, e.g., “setup SRB4 after successful HO execution” as part of the handover procedure.

Below is exemplary text for 3GPP TS 38.413 (v!7.6.0) that adds to a RETRIEVE UE CONTEXT REQUEST message sent by an NG-RAN node 1 to an NG-RAN node 2 a request to retrieve QoE related NW-configuration(s) following a UE attempt to re-establish a connection towards a cell of NG-RAN node 1. Ellipses denote existing elements deleted for brevity.

*** Begin example 3GPP specification text ***

9.1.1.8 RETRIEVE UE CONTEXT REQUEST

This message is sent by the new NG-RAN node to request the old NG-RAN node to transfer the UE Context to the new NG-RAN.

Direction: new NG-RAN node old NG-RAN node.

*** End example 3GPP specification text ***

Below is exemplary text for 3GPP TS 38.423 (v!7.6.0) that adds an indication of available QoE-related information to QMC Configuration Information and UE Application Layer Measurement Configuration Information IES. Ellipses denote existing elements deleted for brevity. The two examples may be used separately or in combination.

*** Begin example 3GPP specification text ***

9.2.3.156 QMC Configuration Information This IE contains the information about the QoE Measurement Collection (QMC) configuration.

9.2.3.157 UE Application Layer Measurement Configuration Information

This IE defines the information about the QoE Measurement Collection (QMC) configuration.

*** End example 3GPP specification text ***

Embodiments of the network-based solution described above are based on source and target RAN nodes being logically or physically different nodes. If the source and target cells are controlled by the same RAN node, the inter-RAN node signal described above can be substantially replicated as internal and implementation-specific (e.g., within CU).

In embodiments of the UE-based solution, the UE informs the target RAN node controlling the target cell that the UE has available stored QoE-related information. When the mobility operation that follows the UE’s transition from RRC IDLE to RRC CONNECTED is a handover, the UE informs the target RAN node during or upon completion of handover execution. In some variants, the UE includes an indication in an RRCReconflgurationComplete message (also referred to as Handover Complete message) that marks the completion of the handover execution. In other variants, the UE includes an indication in an RRCReconflgurationComplete message sent in response to an RRCReconflguration message received in the target cell. In other variants, the UE includes an indication in a UEAssistancelnformation RRC message. Below is some exemplary text for 3GPP TS 38.331 (v!7.6.0) that specifies the UE including the indication in an RRCReconflgurationComplete message upon completion of handover (underline emphasis).

*** Begin example 3GPP specification text ***

5.3.5.3 Reception of an RRCReconflguration by the UE

The UE shall perform the following actions upon reception of the RRCReconflguration, upon execution of the conditional reconfiguration (CHO, CPA, or CPC), or upon execution of an LTM cell switch:

[••] l>else (RRCReconflguration was received via SRB1):

2> if the UE is in NR-DC and;

2> if the RRCReconflguration does not include the mrdc-SecondaryCellGroupConfig'.

3>if the RRCReconflguration includes the scg-State'.

4>perform SCG deactivation as specified in 5.3.5.13b; 3>else:

4>perform SCG activation without SN message as specified in 5.3.5.13bl;

2> if the reconfigurationWithSync was included in spCellConfig of an MCG:

3>if ta-Report or ta-ReportATG is configured with value enabled and the UE supports

TA reporting:

4> indicate TA report initiation to lower layers;

3>if configured with application layer measurements with configforRRC-Idlelnactive set to true and for which appLayerldlelnactiveConfig or application layer measurement report have not been transmitted since the UE entered RRC CONNECTED:

4> include measConfigReportAppLayer Available in the RRCReconfigurationComplete message;

2> submit the RRCReconfigurationComplete message via SRB1 to lower layers for transmission using the new configuration;

[••]

*** End example 3GPP specification text ***

Figure 8 shows an exemplary ASN.1 data structure for an RRCReconfigurationComplete message, according to various embodiments of the present disclosure. Underline indicates portions that have been added relative to the message definition in 3GPP TS 38.331 (vl7.6.0). In particular, the nonCriticalExtension field in the RRCReconfigurationComplete-vl720-IEs is defined to include an RRCReconfiguratoinComplete-vl800-IEs field. According to Figure 8, this field includes a measConfigReportAppLayerAvailable-rl8 IE, which when present has an enumerated value of “true” indicating availability of QoE-related information from when the UE was previously in RRC IDLE or RRC INACTIVE. On the other hand, absence of this IE indicates no QoE-related information is available at the UE.

When the mobility operation that follows the UE’s transition from RRC IDLE to RRC CONNECTED is detection of RLF in the source cell followed by RRC re-establishment in the target cell, the UE informs the target RAN node about the availability of QoE-related information during or after completion of RRC re-establishment execution. For example, the UE may include an indication in any of the following messages:

• RRCReestablishmentComplete message that signals completion of re-establishment;

• RRCReestablishmentRequest message that initiates re-establishment;

• RRCReconfigurationComplete message sent in response to an RRCReconfiguration RRC message received from the target RAN node in the target cell; and

• UEAssistancelnformation RRC message sent to the target RAN node. Figure 9 shows an exemplary ASN.1 data structure for an RRCReestablishmentComplete message, according to various embodiments of the present disclosure. Underline indicates portions that have been added relative to the message definition in 3GPP TS 38.331 (vl7.6.0). In particular, the nonCriticalExtension field in the RRCReestablishmentComplete-vl720-IEs is defined to include an RRCReestablishmentComplete -v!800-IEs field. According to Figure 9, this field includes a measConfigReportAppLayerAvailable-rl8 IE, which when present has an enumerated value of “true” indicating availability of QoE-related information from when the UE was previously in RRC IDLE or RRC INACTIVE. On the other hand, absence of this IE indicates no QoE-related information is available at the UE.

For example, consider that during the RRC re-establishment procedure, the UE sends an indication to the target RAN node indicating that one or more NW QoE configurations are available at the UE, optionally including identifiers of the available NW QoE configurations. After receiving the indication, the target RAN node requests the UE to provide the available NW QoE configurations. In a variant of this scenario, when the new RAN node receives the re-establishment request from the UE, it can attempt to retrieve the NW QoE configuration from the source RAN node that previously served the UE, such as by using a retrieve UE context procedure. For instance, the target RAN node can add a new field such as “Unfetched QMC configurations ” in the RETRIEVE UE CONTEXT REQUEST XnAP message, to indicate interest in retrieving the information.

As another example, the UE received one or more NW QoE configurations while in RRC_CONNECTED with the source RAN node and stored them prior to transitioning to RRC INACTIVE. The UE later attempts to resume towards the source RAN node, which no longer has the UE’s context including the one or more NW QoE configurations previously sent to (and stored by) the UE. Thus, the UE’s resume attempt results in the setup of a new RRC connection in which the RAN node replies to the UE’s RRCResumeRequest message with an RRCSetup message. In this case, the UE sends an RRCSetupComplete message including the indication of the availability of QoE-related information (i.e., the one or more NW QoE configurations) stored at the UE. Based on this indication, the source RAN node is able to retrieve the missing NW QoE configurations from the UE.

A variant of this scenario occurs when the UE attempts the resume towards the target cell served by the target RAN node that is different from the source RAN node, which no longer has the UE’s context including the one or more NW QoE configurations previously sent to (and stored by) the UE. Since the target RAN node cannot retrieve any NW QoE configurations from the source RAN node, it triggers a setup of a new RRC connection for the UE. As in the previous example, the UE sends an RRCSetupComplete message including the indication of the availability of QoE-related information (i.e., the one or more NW QoE configurations) stored at the UE

These two scenarios may be generalized to any scenario where the UE receives an RRCSetup message in response to an RRCResumeRequest (or equivalent) message. When the UE attempts a resume, a possible outcome is that the resume attempt is rejected with an RRCReject message being sent to the UE. This message implicitly or explicitly instructs the UE to retain any stored QoE-related information.

When the UE attempts a resume, another possible outcome is that the resume attempt is rejected with the release of the UE, i.e., an RRCRelease message is sent to the UE. The release can be for transition to RRC IDLE or a release with suspend for transition to RRC INACTIVE. In either case, the RRCRelease message implicitly or explicitly instructs the UE to retain any stored QoE-related information.

In other embodiments, when a UE performs a mobility operation before being able to send all stored QoE-related information (e.g., QoE reports and/or NW QoE configurations) to a serving cell, the UE releases or discards the stored QoE-related information. For example, if a UE transitions from RRC IDLE to RRC CONNECTED and indicates availability of stored NW QoE configurations and/or QoE reports, and is then handed over to or detects RLF and re-establishes the RRC connection in another cell before sending all of this stored QoE-related information, the UE releases its stored QoE-related information.

In some variants, the UE does not release the stored QoE-related information if it received an indication of support for reception of available QoE-related information before the mobility operation, such as an idleInactiveReportAllowed-rl8 field in an RRCReconflguration message, set to “true”. In other variants, the UE may selectively release or discard portions of the QoE-related information, based on network configuration or UE implementation. For example, the UE could determine which NW QoE configurations and/or QoE reports to release based on priority configured by OAM (as per Rel-18 specifications).

A UE should not transmit stored QoE-related information to a RAN node which has not indicated support for receiving UE QoE-related information collected in RRC IDLE or RRC INACTIVE. If the target RAN node is informed that the UE has available QoE-related information that it has not sent to the network since it transitioned from RRC IDLE to RRC_CONNECTED, then the target RAN node should indicate to the UE that transmission of QoE-related information collected in RRC IDLE/RRC INACTIVE is allowed in the target cell (if supported by the target RAN node). This can be done, for example, by including in an RRCReconflguration message (i.e., that establishes SRB4) an IdlelnactiveReportAllowed-r 18 field set to “true”. In some variants, the target RAN node may indicate whether it wants/is able to receive NW QoE configurations, QoE reports, or both. In other variants, the target RAN node may provide selection criteria, based on which the UE should select the QoE-related information to indicate. For example, the new/target RAN node may indicate that it wants to receive the QoE-related information based on one or more of the following criteria:

• service type;

• QoE measurement type, e.g., s-based or m-based;

• whether the QoE configuration has a corresponding RVQoE configuration

• whether any QoE reports are stored; and

• size and/or number of stored QoE reports.

With both the UE-based and the network-based solutions described above, the UE is the only entity that holds the one or more NW QoE configurations it previously received from the source RAN node. Thus, the UE’s handling of this stored information after transmission to the target RAN node needs to be standardized, particularly for when the UE does not completely transmit all stored NW QoE configurations before interruption due to handover, RLF, reestablishment, resume, etc. Furthermore, mobility procedures such as handover, resume, etc. may fail at any point during execution. Therefore, the NW QoE configurations stored by the UE should persist beyond the expected failure conditions to provide continuity of QoE data collection. A stored QoE configuration should only be released by the UE when it has been entirely transferred or when it is explicitly released or modified by the network.

In addition, NW QoE configurations and QoE reports may have different priorities for retention by the UE. For example, QoE reports may have lower retention priority, such that they may be discarded due to lack of memory, possibly in conjunction with relative priority of corresponding QoE configuration. In contrast, NW QoE configurations may have higher retention priority, such that they may be retained at the expense of deleting QoE reports as necessary.

In any of the embodiments described above, UE capability signaling may be defined, to indicate to the network which of the features described herein the UE is able to support.

Various features of the embodiments described above correspond to various operations illustrated in Figures 10-12, which show exemplary methods (e.g, procedures) for a UE, a target RAN node, and a source RAN node, respectively. In other words, various features of the operations described below correspond to various embodiments described above. Furthermore, the exemplary methods shown in Figures 10-12 can be used cooperatively to provide various benefits, advantages, and/or solutions to problems described herein. Although Figures 10-12 show specific blocks in particular orders, the operations of the exemplary methods can be performed in different orders than shown and can be combined and/or divided into blocks having different functionality than shown. Optional blocks or operations are indicated by dashed lines.

In particular, Figure 10 shows an exemplary method (e.g., procedure) for a UE configured to perform QoE measurements in a RAN, according to various embodiments of the present disclosure. The exemplary method can be performed by a UE (e.g., wireless device, etc.) such as described elsewhere herein.

The exemplary method includes the operations of block 1020, where the UE obtains and stores QoE-related information, e.g., from the RAN. The exemplary method also includes the operations of block 1030, where the UE subsequently connects to a first cell served by a first RAN node. The exemplary method also includes the operations of block 1050, where while at least a portion of the stored QoE-related information has not been sent to the first RAN node, the UE performs a mobility operation from the first cell (e.g., as source cell) to a second cell (e.g., as target cell) served by a second RAN node. The exemplary method also includes the operations of block 1060, where the UE sends to the second RAN node an indication of QoE-related information available to be fetched from the UE.

• one or more network (NW) QoE measurement collection (QMC) configurations maintained by the RAN to facilitate QoE measurements by the UE (also referred to above as “NW QoE configurations”); and

In some of these embodiments, obtaining the QoE-related information in block 1020 includes the following operations, labelled with corresponding sub-block numbers:

• (1021) receiving the one or more NW QMC configurations from the RAN while in a connected state with respect to the RAN;

• (1022) subsequently transitioning to a non-connected state with respect to the RAN; and

• (1023) performing the QoE measurements while in the non-connected state before connecting to the first cell in block 1030.

In some variants of these embodiments, the QoE measurements are performed for one or more applications carried by a broadcast service received by the UE while operating in the nonconnected state. In some variants of these embodiments, the exemplary method also includes the operations of block 1040, where while connected to the first cell and before the mobility operation (e.g., block 1050), the UE receives from the first RAN node a message indicating support for reception of QoE-related information stored by the UE while in the non-connected state.

In some embodiments, the exemplary method also includes the operations of block 1045, where while connected to the first cell and before the mobility operation (e.g., block 1050), the UE sends a subset of the QoE-related information to the first RAN node. In other embodiments, the exemplary method also includes the operations of block 1035, where the UE selectively discards a subset of the stored QoE-related information, based on priority information associated with the stored QoE-related information.

In some embodiments, the mobility operation is a handover, and the indication of QoE- related information available to be fetched from the UE is sent to the second RAN node in one of the following messages:

• a UE assistance information message.

Various examples of these messages were discussed above.

In other embodiments, performing the mobility operation in block 1050 includes the operations of sub-block 1052, where the UE detects a radio link failure (RLF) in the first cell and reestablishes the UE’s connection with the RAN in the second cell. In such case, the indication of QoE-related information available to be fetched from the UE is sent to the second RAN node in one of the following messages:

• a message that requests connection reestablishment in the second cell;

• a reestablishment complete message that indicates UE completion of connection reestablishment in the second cell;

• a UE assistance information message.

Various examples of these messages were discussed above.

In other embodiments, the non-connected state is RRC INACTIVE and performing the mobility operation in block 1050 includes the following operations, labelled with corresponding sub-block numbers:

• (1053) sending to the second RAN node a request to resume the UE’s connection with the RAN in the second cell; and

• (1054) receiving from the second RAN node a first message indicating that the request to resume the UE’s connection is rejected.

The indication of QoE-related information available to be fetched from the UE is included in a second message sent after receiving the first message. In some of these embodiments, the first message is an RRCSetup message that also indicates a new connection for the UE will be set up in the second cell, and the second message is a RRCSetupComplete message indicating UE completion of connection setup in the second cell.

In other of these embodiments, the first message is one of the following: an RRCRelease message, or an RRCRelease message that also indicates the UE’s connection with the RAN is released or suspended. Additionally, the second message is sent during or after setup of a new connection for the UE in the second cell. In some variants of these embodiments, the first message explicitly or implicitly indicates that the UE should retain the stored QoE-related information after UE’s connection with the RAN is released or suspended.

In some embodiments, the exemplary method also includes the following operations, labelled with corresponding block numbers:

• (1070) in response to the indication of QoE-related information available to be fetched from the UE, receiving from the second RAN node a request for the QoE-related information available to be fetched from the UE; and

• (1080) sending the available QoE-related information to the second RAN node in response to the request.

In some of these embodiments, the request is, or is included in, an RRCReconflguration message that establishes signaling radio bearer 4 (SRB4).

In addition, Figure 11 shows an exemplary method (e.g., procedure) for a second RAN node configured to manage QoE measurements by UEs operating in the RAN, according to various embodiments of the present disclosure. The exemplary method can be performed by a RAN node (e.g., base station, eNB, gNB, ng-eNB, TRP, etc.) such as described elsewhere herein.

The exemplary method includes the operations of block 1110, where the second RAN node performs or facilitates a mobility operation for a UE from a first cell (e.g., as source cell) served by a first RAN node to a second cell (e.g., as target cell) served by the second RAN node. The exemplary method also includes the operations of block 1120, where the second RAN node receives an indication of QoE-related information available to be fetched from the UE. The QoE- related information was obtained and stored by the UE before the UE connected to the first cell, and at least a portion of the stored QoE-related information has not been sent (e.g., by the UE) to the first RAN node before the mobility operation. In some embodiments, the indication is received from the UE. In other embodiments, the indication is received from the first RAN node.

• one or more NW QMC configurations maintained by the RAN to facilitate QoE measurements by the UE; and • one or more QoE reports based on QoE measurements performed by the UE in accordance with one or more UE QMC configurations.

In some of these embodiments, one or more of the following applies:

• the one or more NW QMC configurations were received by the UE from the first RAN node while in a connected state with respect to the RAN; and

• the one or more QoE reports are based on QoE measurements performed by the UE while in the non-connected state before connecting to the first cell.

In some variants of these embodiments, the QoE measurements are for one or more applications carried by a broadcast service received by the UE while operating in the nonconnected state. In some variants of these embodiments, the mobility operation is performed or facilitated after the UE obtains and stores the QoE-related information and transitions back to the connected state with respect to the first cell.

In some embodiments, the mobility operation is a handover, and the indication of QoE- related information available to be fetched from the UE is received in one of the following messages:

• from the UE in a message that indicates UE completion of handover execution to the second cell;

• from the UE in a reconfiguration complete message responsive to a reconfiguration message sent by the second RAN node;

• from the UE in a UE assistance information message;

• from the first RAN node in a handover request message;

• from the first RAN node in a handover required message;

• from the first RAN node in a handover preparation information message; or

• from the first RAN node in a request to set up signaling radio bearer 4 (SRB4) for the UE in the second cell.

Various examples of these different messages were discussed above.

In other embodiments, the mobility operation is a reestablishment of the UE’s connection with the RAN in the second cell after the UE detected a RLF in the first cell. The indication of QoE-related information available to be fetched from the UE is received in one of the following messages:

• from the UE in a message that requests connection reestablishment in the second cell;

• from the UE in a reestablishment complete message that indicates UE completion of connection reestablishment in the second cell; • from the UE in a reconfiguration complete message responsive to a reconfiguration message sent by the second RAN node;

• from the UE in a UE assistance information message; or

• from the first RAN node in a retrieve UE context response message. Various examples of these different messages were discussed above.

In other embodiments, performing or facilitating the mobility operation in block 1110 includes the following operations, labelled with corresponding sub-block numbers:

• (1111) receiving from the UE a request to resume the UE’s connection with the RAN in the second cell; and

• (1112) sending to the UE a first message indicating that the request to resume the UE’s connection is rejected; and

The indication of QoE-related information available to be fetched from the UE is included in a second message received after sending the first message.

In other of these embodiments, the first message is one of the following: an RRCReject message, or an RRCRelease message that also indicates the UE’s connection with the RAN is released or suspended. Also, the second message is sent during or after setup of a new connection for the UE in the second cell. In some variants of these embodiments, the first message explicitly or implicitly indicates that the UE should retain the stored QoE-related information after UE’s connection with the RAN is released or suspended.

• (1130) in response to the indication of QoE-related information available to be fetched from the UE, sending to the UE a request for the QoE-related information available to be fetched from the UE; and

• (1140) receiving the available QoE-related information from the UE in response to the request.

In addition, Figure 12 shows an exemplary method (e.g., procedure) for a first RAN node configured to manage QoE measurements by UEs operating in the RAN, according to various embodiments of the present disclosure. The exemplary method can be performed by a RAN node (e.g., base station, eNB, gNB, ng-eNB, TRP. etc.) such as described elsewhere herein. The exemplary method includes the operations of block 1250, where the first RAN node performs or facilitates a mobility operation for a UE from a first cell (e.g., as source cell) served by the first RAN node to a second cell (e.g., as target cell) served by a second RAN node. The exemplary method also includes the operations of block 1260, where the first RAN node sends to the second RAN node an indication of QoE-related information available to be fetched from the UE. The QoE-related information was obtained and stored by the UE while operating in the first cell, and at least a portion of the stored QoE-related information has not been sent to the first RAN node.

• one or more NW QMC configurations maintained by the RAN to facilitate QoE measurements by the UE; and

In some of these embodiments, the exemplary method also includes the operations of blocks 1210-1215, where the first RAN node sends the one or more NW QMC configurations to the UE while the UE is in a connected state with respect to the RAN, and subsequently transitions the UE to a non-connected state with respect to the RAN. In some of these embodiments, the one or more QoE reports are based on QoE measurements performed by the UE while operating in the non-connected state with respect to the RAN.

In some variants of these embodiments, the QoE measurements are performed by the UE for one or more applications carried by a broadcast service transmitted by the first RAN node via the first cell. In some variants of these embodiments, the exemplary method also includes the operations of block 1220, where the first RAN node connects with the UE via the first cell. The mobility operation is performed or facilitated in block 1250 after connecting with the UE via the first cell in block 1220.

In some further variants, the exemplary method also includes the operations of block 1240, where the first RAN node receives a subset of the QoE-related information from the UE, connecting with the UE via the first cell in block 1220. In still further variants, the exemplary method also includes the operations of block 1230, where the first RAN node sends to the UE a message indicating support for reception of QoE-related information stored by the UE while in a non-connected state. The subset of QoE-related information is received from the UE in block 1240 responsive to the message in block 1230.

In some embodiments, the mobility operation is a handover, and the indication of QoE- related information available to be fetched from the UE is sent to the second RAN node in one of the following messages: • a handover request message;

• a handover required message;

• a handover preparation information message; or

• a request to set up signaling radio bearer 4 (SRB4) for the UE in the second cell.

In other embodiments, the mobility operation is a reestablishment of the UE’s connection with the RAN in the second cell after the UE detected a radio link failure (RLF) in the first cell. Also, the indication of QoE-related information available to be fetched from the UE is sent to the second RAN node in a retrieve UE context response message.

In other embodiments, the non-connected state is RRC INACTIVE and performing or facilitating the mobility operation in block 1250 includes the following operations, labelled with corresponding sub-block numbers:

• (1251) receiving from the UE a request to resume the UE’s connection with the RAN in the first cell; and

• (1252) sending to the UE a first message indicating that the request to resume the UE’s connection is rejected.

In some of these embodiments, the first message is one of the following: an RRCReject message, or an RRCRelease message that also indicates the UE’s connection with the RAN is released or suspended. In some variants of these embodiments, the first message explicitly or implicitly indicates that the UE should retain the stored QoE-related information after UE’s connection with the RAN is released or suspended.

Although various embodiments and variants are described above in terms of methods, techniques, and/or procedures, the person of ordinary skill will readily comprehend that such methods, techniques, and/or procedures can be embodied by various combinations of hardware and software in various systems, communication devices, computing devices, control devices, apparatuses, non-transitory computer-readable media, computer program products, etc.

Figure 13 shows an example of a communication system 1300 in accordance with some embodiments. In this example, communication system 1300 includes a telecommunication network 1302 that includes an access network 1304 (e.g., RAN) and a core network 1306, which includes one or more core network nodes 1308. Access network 1304 includes one or more access network nodes, such as network nodes 1310a-b (one or more of which may be generally referred to as network nodes 1310), or any other similar 3GPP access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, telecommunication network 1302 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in telecommunication network 1302 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in telecommunication network 1302, including one or more network nodes 1310 and/or core network nodes 1308.

Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O-CU- CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e. g. , r App), or any combination thereof (the adj ective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an Al, Fl, Wl, El, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include an O-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O-RAN Alliance or comparable technologies. Network nodes 1310 facilitate direct or indirect connection of UEs, such as by connecting UEs 1312a-d (one or more of which may be generally referred to as UEs 1312) to core network 1306 over one or more wireless connections.

Example wireless communications over a wireless connection include transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, communication system 1300 may include any number of wired or wireless networks, network nodes, UEs, and/or any other components or systems that may facilitate or participate in the communication of data and/or signals whether via wired or wireless connections. Communication system 1300 may include and/or interface with any type of communication, telecommunication, data, cellular, radio network, and/or other similar type of system.

UEs 1312 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and/or operable to communicate wirelessly with network nodes 1310 and other communication devices. Similarly, network nodes 1310 are arranged, capable, configured, and/ or operable to communicate directly or indirectly with UEs 1312 and/ or with other network nodes or equipment in telecommunication network 1302 to enable and/or provide network access, such as wireless network access, and/or to perform other functions, such as administration in telecommunication network 1302.

In the depicted example, core network 1306 connects network nodes 1310 to one or more hosts, such as host 1316. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. Core network 1306 includes one or more core network nodes (e.g., 1308) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and/or hosts, such that the descriptions thereof are generally applicable to the corresponding components of core network node 1308. Example core network nodes include Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security Edge Protection Proxy (SEPP), Network Exposure Function (NEF), and/or a User Plane Function (UPF).

Host 1316 may be under the ownership or control of a service provider other than an operator or provider of access network 1304 and/or telecommunication network 1302, and may be operated by the service provider or on behalf of the service provider. Host 1316 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio/video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

As a whole, communication system 1300 of Figure 13 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and/or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and/or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and/or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox. In some examples, telecommunication network 1302 is a cellular network that implements 3GPP standardized features. Accordingly, telecommunication network 1302 may support network slicing to provide different logical networks to different devices that are connected to telecommunication network 1302. For example, telecommunication network 1302 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and/or Massive Machine Type Communication (mMTC)/Massive loT services to yet further UEs.

In some examples, UEs 1312 are configured to transmit and/or receive information without direct human interaction. For instance, a UE may be designed to transmit information to access network 1304 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from access network 1304. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. For example, a UE may operate with any one or combination of Wi-Fi, NR (New Radio) and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) New Radio - Dual Connectivity (EN-DC).

In the example, hub 1314 communicates with access network 1304 to facilitate indirect communication between one or more UEs (e.g., 1312c and/or 1312d) and network nodes (e.g., 1310b). In some examples, hub 1314 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, hub 1314 may be a broadband router enabling access to core network 1306 for the UEs. As another example, hub 1314 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 1310, or by executable code, script, process, or other instructions in hub 1314. As another example, hub 1314 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, hub 1314 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, hub 1314 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which hub 1314 then provides to the UE either directly, after performing local processing, and/or after adding additional local content. In still another example, hub 1314 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy loT devices.

Hub 1314 may have a constant/persistent or intermittent connection to network node 1310b. Hub 1314 may also allow for a different communication scheme and/or schedule between hub 1314 and UEs (e.g., 1312c and/or 1312d), and between hub 1314 and core network 1306. In other examples, hub 1314 is connected to core network 1306 and/or one or more UEs via a wired connection. Moreover, hub 1314 may be configured to connect to an M2M service provider over access network 1304 and/or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with network nodes 1310 while still connected via hub 1314 via a wired or wireless connection. In some embodiments, hub 1314 may be a dedicated hub - that is, a hub whose primary function is to route communications to/from the UEs from/to network node 1310b. In other embodiments, hub 1314 may be a non-dedicated hub - that is, a device which is capable of operating to route communications between the UEs and network node 1310b, but which is additionally capable of operating as a communication start and/or end point for certain data channels.

In some embodiments, any of UEs 1312 may be configured to perform operations attributed to a UE in various methods or procedures described above, including the exemplary method shown in Figure 10. In some embodiments, any of network nodes 1010 may be configured to perform operations attributed to a RAN node in various methods or procedures described above, including the exemplary methods shown in Figures 11-12.

Figure 14 shows a UE 1400 in accordance with some embodiments. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, voice over IP (VoIP) phone, wireless local loop phone, desktop computer, personal digital assistant (PDA), wireless cameras, gaming console or device, music storage device, playback appliance, wearable terminal device, wireless endpoint, mobile station, tablet, laptop, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart device, wireless customer-premise equipment (CPE), vehicle, vehicle-mounted or vehicle embedded/integrated wireless device, etc. Other examples include any UE identified by 3GPP, including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and/or an enhanced MTC (eMTC) UE.

A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle-to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and/or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

UE 1400 includes processing circuitry 1402 that is operatively coupled via a bus 1404 to input/output interface 1406, power source 1408, memory 1410, communication interface 1412, and possibly other components not explicitly shown. Certain UEs may utilize all or a subset of the components shown in Figure 14. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

Processing circuitry 1402 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in memory 1410. Processing circuitry 1402 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, processing circuitry 1402 may include multiple central processing units (CPUs).

In the example, input/output interface 1406 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and/or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into UE 1400. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

In some embodiments, power source 1408 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. Power source 1408 may further include power circuitry for delivering power from power source 1408 itself, and/or an external power source, to the various parts of UE 1400 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging power source 1408. Power circuitry may perform any formatting, converting, or other modification to the power from power source 1408 to make the power suitable for the respective components of UE 1400 to which power is supplied.

Memory 1410 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, memory 1410 includes one or more application programs 1414, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 1416. Memory 1410 may store, for use by UE 1400, any of a variety of various operating systems or combinations of operating systems.

Memory 1410 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD-DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and/or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ Memory 1410 may allow UE 1400 to access instructions, application programs and the like, stored on transitory or non- transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in memory 1410, which may be or comprise a device-readable storage medium.

Processing circuitry 1402 may be configured to communicate with an access network or other network using communication interface 1412. Communication interface 1412 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 1422. Communication interface 1412 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include transmitter 1418 and/or receiver 1420 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, transmitter 1418 and receiver 1420 may be coupled to one or more antennas (e.g., antenna 1422) and may share circuit components, software, or firmware, or alternatively be implemented separately.

In the illustrated embodiment, communication functions of communication interface 1412 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented according to one or more communication protocols and/or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code Division Multiple Access (WCDMA), GSM, LTE, New Radio (NR), UMTS, WiMax, Ethernet, transmission control protocol/intemet protocol (TCP/IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 1412, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

A UE, when in the form of an Internet of Things (loT) device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an loT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, an electricity meter, a robot vacuum cleaner, a voice controlled smart speaker, a home security camera, a motion detector, a thermostat, a smoke detector, a door/window sensor, a flood/moisture sensor, an electrical door lock, a connected doorbell, an air conditioning system like a heat pump, an autonomous vehicle, a surveillance system, a weather monitoring device, a vehicle parking monitoring device, an electric vehicle charging station, a smart watch, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, a water sprinkler, an animal- or item-tracking device, a sensor for monitoring a plant or animal, an industrial robot, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an loT device comprises circuitry and/or software in dependence of the intended application of the loT device in addition to other components as described in relation to UE 1400 shown in Figure 14.

As yet another specific example, in an loT scenario, a UE may represent a machine or other device that performs monitoring and/or measurements, and transmits the results of such monitoring and/or measurements to another UE and/or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and/or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

In some embodiments, UE 1400 may be configured to perform operations attributed to a UE in various methods or procedures described above, including the exemplary method shown in Figure 10.

Figure 15 shows a network node 1500 in accordance with some embodiments. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (e.g., radio base stations, Node Bs, eNBs, gNBs), and O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and/or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS). Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell/multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and/or Minimization of Drive Tests (MDTs).

Network node 1500 includes processing circuitry 1502, memory 1504, communication interface 1506, and power source 1508. Network node 1500 may be composed of multiple physically separate components (e.g., a NodeB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which network node 1500 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NodeBs. In such a scenario, each unique NodeB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, network node 1500 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1504 for different RATs) and some components may be reused (e.g., a same antenna 1510 may be shared by different RATs). Network node 1500 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1500, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1500.

Processing circuitry 1502 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and/or encoded logic operable to provide, either alone or in conjunction with other network node 1500 components, such as memory 1504, to provide network node 1500 functionality.

In some embodiments, processing circuitry 1502 includes a system on a chip (SOC). In some embodiments, processing circuitry 1502 includes one or more of radio frequency (RF) transceiver circuitry 1512 and baseband processing circuitry 1514. In some embodiments, RF transceiver circuitry 1512 and baseband processing circuitry 1514 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1512 and baseband processing circuitry 1514 may be on the same chip or set of chips, boards, or units.

Memory 1504 may comprise any form of volatile or non-volatile computer-readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), read-only memory (ROM), mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and/or any other volatile or non-volatile, non-transitory device-readable and/or computer-executable memory devices that store information, data, and/or instructions that may be used by processing circuitry 1502. Memory 1504 may store any suitable instructions, data, or information, including a computer program, software, an application including logic, rules, code, tables, and/or other instructions (collected denoted computer program 1504a, which may be in the form of a computer program product) capable of being executed by processing circuitry 1502 and utilized by network node 1500. Memory 1504 may be used to store any calculations made by processing circuitry 1502 and/or any data received via communication interface 1506. In some embodiments, processing circuitry 1502 and memory 1504 is integrated.

Communication interface 1506 is used in wired or wireless communication of signaling and/or data between a network node, access network, and/or UE. As illustrated, communication interface 1506 comprises port(s)/terminal(s) 1516 to send and receive data, for example to and from a network over a wired connection. Communication interface 1506 also includes radio frontend circuitry 1518 that may be coupled to, or in certain embodiments a part of, antenna 1510. Radio front-end circuitry 1518 comprises filters 1520 and amplifiers 1522. Radio front-end circuitry 1518 may be connected to an antenna 1510 and processing circuitry 1502. The radio front-end circuitry may be configured to condition signals communicated between antenna 1510 and processing circuitry 1502. Radio front-end circuitry 1518 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. Radio front-end circuitry 1518 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1520 and/or amplifiers 1522. The radio signal may then be transmitted via antenna 1510. Similarly, when receiving data, antenna 1510 may collect radio signals which are then converted into digital data by radio front-end circuitry 1518. The digital data may be passed to processing circuitry 1502. In other embodiments, the communication interface may comprise different components and/or different combinations of components.

In certain alternative embodiments, network node 1500 does not include separate radio front-end circuitry 1518, instead, processing circuitry 1502 includes radio front-end circuitry and is connected to antenna 1510. Similarly, in some embodiments, all or some of RF transceiver circuitry 1512 is part of communication interface 1506. In still other embodiments, communication interface 1506 includes one or more ports or terminals 1516, radio front-end circuitry 1518, and RF transceiver circuitry 1512, as part of a radio unit (not shown), and communication interface 1506 communicates with baseband processing circuitry 1514, which is part of a digital unit (not shown).

Antenna 1510 may include one or more antennas, or antenna arrays, configured to send and/or receive wireless signals. Antenna 1510 may be coupled to radio front-end circuitry 1518 and may be any type of antenna capable of transmitting and receiving data and/or signals wirelessly. In certain embodiments, antenna 1510 is separate from network node 1500 and connectable to network node 1500 through an interface or port.

Antenna 1510, communication interface 1506, and/or processing circuitry 1502 may be configured to perform any receiving operations and/or certain obtaining operations described herein as being performed by the network node. Any information, data and/or signals may be received from a UE, another network node and/or any other network equipment. Similarly, antenna 1510, communication interface 1506, and/or processing circuitry 1502 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and/or signals may be transmitted to a UE, another network node and/or any other network equipment.

Power source 1508 provides power to the various components of network node 1500 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). Power source 1508 may further comprise, or be coupled to, power management circuitry to supply the components of network node 1500 with power for performing the functionality described herein. For example, network node 1500 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of power source 1508. As a further example, power source 1508 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

Embodiments of network node 1500 may include additional components beyond those shown in Figure 15 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and/or any functionality necessary to support the subject matter described herein. For example, network node 1500 may include user interface equipment to allow input of information into network node 1500 and to allow output of information from network node 1500. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for network node 1500. In some embodiments, network node 1500 may be configured to perform operations attributed to a RAN node in various methods or procedures described above, including the exemplary methods shown in Figures 11-12.

Figure 16 is a block diagram illustrating virtualization environment 1600 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1600 hosted by one or more hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1600 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface.

Applications 1602 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment 1600 to implement some of the features, functions, and/or benefits of some of the embodiments disclosed herein. For example, in some embodiments, one or more virtual nodes 1602 may be configured to perform operations attributed to a RAN node in various methods or procedures described above, including the exemplary methods shown in Figures 11- 12.

Hardware 1604 includes processing circuitry, memory that stores software and/or instructions (collected denoted computer program 1604a, which may be in the form of a computer program product) executable by hardware processing circuitry, and/or other hardware devices as described herein, such as a network interface, input/output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1606 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1608a-b (one or more of which may be generally referred to as VMs 1608), and/or perform any of the functions, features and/or benefits described in relation with some embodiments described herein. Virtualization layer 1606 may present a virtual operating platform that appears like networking hardware to the VMs 1608. VMs 1608 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1606. Different embodiments of the instance of a virtual appliance 1602 may be implemented on one or more of VMs 1608, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

In the context of NFV, each VM 1608 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each VM 1608, and that part of hardware 1604 that executes that VM, be it hardware dedicated to that VM and/or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1608 on top of the hardware 1604 and corresponds to the application 1602.

Hardware 1604 may be implemented in a standalone network node with generic or specific components. Hardware 1604 may implement some functions via virtualization. Alternatively, hardware 1604 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration function 1610, which, among others, oversees lifecycle management of applications 1602. In some embodiments, hardware 1604 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1612 which may alternatively be used for communication between hardware nodes and radio units.

The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, and procedures that, although not explicitly shown or described herein, embody the principles of the disclosure and can be thus within the spirit and scope of the disclosure. Various embodiments can be used together with one another, as well as interchangeably therewith, as should be understood by those having ordinary skill in the art. The term unit, as used herein, can have conventional meaning in the field of electronics, electrical devices and/or electronic devices and can include, for example, electrical and/or electronic circuitry, devices, modules, processors, memories, logic solid state and/or discrete devices, computer programs or instructions for carrying out respective tasks, procedures, computations, outputs, and/or displaying functions, and so on, as such as those that are described herein.

Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

As described herein, device and/or apparatus can be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device or apparatus, instead of being hardware implemented, be implemented as a software module such as a computer program or a computer program product comprising executable software code portions for execution or being run on a processor. Furthermore, functionality of a device or apparatus can be implemented by any combination of hardware and software. A device or apparatus can also be regarded as an assembly of multiple devices and/or apparatuses, whether functionally in cooperation with or independently of each other. Moreover, devices and apparatuses can be implemented in a distributed fashion throughout a system, so long as the functionality of the device or apparatus is preserved. Such and similar principles are considered known by a skilled person.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In addition, certain terms used in the present disclosure, including the specification and drawings, can be used synonymously in certain instances (e.g., “data” and “information”). It should be understood that although these terms (and/or other similar terms) can be used synonymously herein, there can be instances when such words can be intended to not be used synonymously.

Embodiments of the techniques and apparatus described herein also include, but are not limited to, the following enumerated examples:

Al. A method for a user equipment (UE) configured to perform quality-of-experience (QoE) measurements in a radio access network (RAN), the method comprising: obtaining and storing QoE-related information while operating in a source cell served by a source RAN node; while at least a portion of the stored QoE-related information has not been sent to the source RAN node, performing a mobility operation from the source cell to a target cell served by a target RAN node; and sending, to the target RAN node, an indication of QoE-related information available to be fetched from the UE.

A2. The method of embodiment Al, wherein the QoE-related information includes one or more of the following: one or more network (NW) QoE measurement collection (QMC) configurations used by the source RAN node to facilitate QoE measurements by the UE; and one or more QoE reports based on QoE measurements performed by the UE in accordance with one or more UE QMC configurations.

A3. The method of embodiment A2, wherein obtaining the QoE-related information includes one or more of the following: while transitioning from a connected state to a non-connected state with respect to the source cell, receiving the one or more NW QMC configurations from the source RAN node; and performing the QoE measurements while operating in the non-connected state with respect to the source cell. A3a. The method of embodiment A3, wherein the QoE measurements are performed for one or more applications carried by a broadcast service received by the UE while operating in the non-connected state.

A3b. The method of any of embodiments A3-A3a, further comprising, before transitioning from the connected state to the non-connected state, receiving from the source RAN node a message indicating support for reception of QoE-related information stored by the UE while in a non-connected state, wherein storing the QoE-related information is responsive to the message.

A3c. The method of any of embodiments A3-A3b, further comprising, after obtaining the QoE-related information, transitioning back to the connected state from the non-connected state with respect to the source cell, wherein the mobility operation is performed after transitioning back to the connected state.

A3d. The method of embodiment A3c, further comprising, while back in the connected state, sending a subset of the QoE-related information to the source RAN node.

A3e. The method of embodiment A3c, wherein performing the mobility operation comprises selectively discarding a subset of the stored QoE-related information, based on priority information associated with the stored QoE-related information.

A4. The method of any of embodiments Al-A3e, wherein the mobility operation is a handover, and the indication of QoE-related information available to be fetched from the UE is sent to the target RAN node in one of the following messages: a message that indicates UE completion of handover execution to the target cell; a reconfiguration complete message responsive to a reconfiguration message received from the target RAN node; or a UE assistance information message.

A5. The method of any of embodiments Al-A3e, wherein: performing the mobility operation comprises detecting a radio link failure (RLF) in the source cell and reestablishing the UE’s connection with the RAN in the target cell; and the indication of QoE-related information available to be fetched from the UE is sent to the target RAN node in one of the following messages: a message that requests connection reestablishment in the target cell; a message that indicates UE completion of connection reestablishment in the target cell; a reconfiguration complete message responsive to a reconfiguration message received from the target RAN node; or a UE assistance information message.

A6. The method of any of embodiments Al-A3e, wherein: the non-connected state is RRC INACTIVE; performing the mobility operation comprises: sending to the target RAN node a request to resume the UE’s connection with the RAN in the target cell; receiving from the target RAN node a first message indicating that the request to resume the UE’s connection is rejected; and subsequently sending to the target RAN node a second message including the indication of QoE-related information available to be fetched from the UE.

A6a. The method of embodiment A6, wherein the first message is an RRCSetup message that also indicates a new connection for the UE will be set up in the target cell, and the second message is a RRCSetupComplete message indicating UE completion of connection setup in the target cell.

A6b. The method of embodiment A6, wherein: the first message is one of the following: an RRCRelease message that also indicates the UE’s connection with the RAN is released or suspended; and the second message is sent during or after setup of a new connection for the UE in the target cell

A6c. The method of embodiment A6b, where the first message explicitly or implicitly indicates that the UE should retain the stored QoE-related information after UE’s connection with the RAN is released or suspended.

A7. The method of any of embodiments Al-A6c, further comprising: in response to the indication, receiving from the target RAN node a request for the stored QoE-related information; and sending the QoE-related information to the target RAN node in response to the request.

A8. The method of embodiment A7, wherein the request is, or is included in, an RRCReconflguration message that establishes signaling radio bearer 4 (SRB4).

Bl . A method for a target radio access network (RAN) node configured to manage quality - of-experience (QoE) measurements by user equipment (UEs) in the RAN, the method comprising: performing or facilitating a mobility operation for a UE from a source cell served by a source RAN node to a target cell served by the target RAN node; and receiving an indication of QoE-related information available to be fetched from the UE, wherein: the QoE-related information was obtained and stored by the UE while operating in the source cell, and at least a portion of the stored QoE-related information has not been sent to the source RAN node.

B2. The method of embodiment Bl, wherein the indication is received from one of the following: the UE, or the source RAN node.

B3. The method of any of embodiments B1-B2, wherein the QoE-related information includes one or more of the following: one or more network (NW) QoE measurement collection (QMC) configurations used by the source RAN node to facilitate QoE measurements by the UE; and one or more QoE reports based on QoE measurements performed by the UE in accordance with one or more UE QMC configurations.

B4. The method of embodiment B3, wherein one or more of the following applies: the one or more NW QMC configurations were received by the UE from the source RAN node while transitioning from a connected state to a non-connected state with respect to the source cell; and the one or more QoE reports are based on QoE measurements performed by the UE while operating in the non-connected state with respect to the source cell. B4a. The method of embodiment B4, wherein the QoE measurements are for one or more applications carried by a broadcast service received by the UE while operating in the nonconnected state.

B4b. The method of any of embodiments B4-B4a, wherein the mobility operation is performed or facilitated after the UE obtains and stores the QoE-related information and transitions back to the connected state with respect to the source cell.

B5. The method of any of embodiments Bl-B4b, wherein the mobility operation is a handover, and the indication of QoE-related information available to be fetched from the UE is received in one of the following messages: from the UE in a message that indicates UE completion of handover execution to the target cell; from the UE in a reconfiguration complete message responsive to a reconfiguration message sent by the target RAN node; from the UE in a UE assistance information message; from the source RAN node in a handover request message; from the source RAN node in a handover required message; from the source RAN node in a handover preparation information message; or from the source RAN node in a request to set up signaling radio bearer 4 (SRB4) for the UE in the target cell.

B6. The method of any of embodiments Bl-B4b, wherein: the mobility operation is a reestablishment of the UE’s connection with the RAN in the target cell after the UE detected a radio link failure (RLF) in the source cell; and the indication of QoE-related information available to be fetched from the UE is received in one of the following messages: from the UE in a message that requests connection reestablishment in the target cell; from the UE in a message that indicates UE completion of connection reestablishment in the target cell; from the UE in a reconfiguration complete message responsive to a reconfiguration message sent by the target RAN node; from the UE in a UE assistance information message; or from the source RAN node in a retrieve UE context response message.

B7. The method of any of embodiments Bl-B4b, wherein: the non-connected state is RRC INACTIVE; and performing or facilitating the mobility operation comprises: receiving from the UE a request to resume the UE’s connection with the RAN in the target cell; sending to the UE a first message indicating that the request to resume the UE’s connection is rejected; and subsequently receiving from the UE a second message including the indication of QoE-related information available to be fetched from the UE.

B7a. The method of embodiment B7, wherein the first message is an RRCSetup message that also indicates a new connection for the UE will be set up in the target cell, and the second message is a RRCSetupComplete message indicating UE completion of connection setup in the target cell.

B7b. The method of embodiment B7, wherein: the first message is one of the following: an RRCReject message, or an RRCRelease message that also indicates the UE’s connection with the RAN is released or suspended; and the second message is sent during or after setup of a new connection for the UE in the target cell

B7c. The method of embodiment B7b, where the first message explicitly or implicitly indicates that the UE should retain the stored QoE-related information after UE’s connection with the RAN is released or suspended.

B8. The method of any of embodiments Bl-B7c, further comprising: in response to the indication, sending to the UE a request for the stored QoE-related information; and receiving the QoE-related information from the UE in response to the request.

B9. The method of embodiment B8, wherein the request is, or is included in, an RRCReconflguration message that establishes signaling radio bearer 4 (SRB4). Cl . A method for a source radio access network (RAN) node configured to manage quality - of-experience (QoE) measurements by user equipment (UEs) in the RAN, the method comprising: performing or facilitating a mobility operation for a UE from a source cell served by the source RAN node to a target cell served by a target RAN node; and sending to the target RAN node an indication of QoE-related information available to be fetched from the UE, wherein: the QoE-related information was obtained and stored by the UE while operating in the source cell, and at least a portion of the stored QoE-related information has not been received by the source RAN node.

C2. The method of embodiment Cl, wherein the QoE-related information includes one or more of the following: one or more network (NW) QoE measurement collection (QMC) configurations used by the source RAN node to facilitate QoE measurements by the UE; and one or more QoE reports based on QoE measurements performed by the UE in accordance with one or more UE QMC configurations.

C3. The method of embodiment C2, wherein one or more of the following applies: the method further comprising sending the one or more NW QMC configurations to the UE while transitioning the UE from a connected state to a non-connected state with respect to the source cell; and the one or more QoE reports are based on QoE measurements performed by the UE while operating in the non-connected state with respect to the source cell.

C3a. The method of embodiment C3, wherein the QoE measurements are performed by the UE for one or more applications carried by a broadcast service transmitted by the source RAN node via the source cell.

C3b. The method of any of embodiments C3-C3a, further comprising, before transitioning the UE from the connected state to the non-connected state, sending to the UE a message indicating support for reception of QoE-related information stored by the UE while in a non-connected state, wherein the QoE-related information is stored by the UE responsive to the message. C3c. The method of any of embodiments C3-C3b, further comprising, after the UE obtains the QoE-related information, transitioning the UE back to the connected state from the nonconnected state with respect to the source cell, wherein the mobility operation is performed or facilitated after transitioning the UE back to the connected state.

C3d. The method of embodiment C3c, further comprising receiving a subset of the QoE- related information from the UE, after the UE is back in the connected state.

C4. The method of any of embodiments Cl-C3d, wherein the mobility operation is a handover, and the indication of QoE-related information available to be fetched from the UE is sent to the target RAN node in one of the following messages: a handover request message; a handover required message; a handover preparation information message; or a request to set up signaling radio bearer 4 (SRB4) for the UE in the target cell.

C5. The method of any of embodiments Cl-C3d, wherein: the mobility operation is a reestablishment of the UE’s connection with the RAN in the target cell after the UE detected a radio link failure (RLF) in the source cell; and the indication of QoE-related information available to be fetched from the UE is sent to the target RAN node in a retrieve UE context response message.

C6. The method of any of embodiments Cl-C3d, wherein: the non-connected state is RRC INACTIVE; performing or facilitating the mobility operation comprises: receiving from the UE a request to resume the UE’s connection with the RAN in the source cell; and sending to the UE a first message indicating that the request to resume the UE’s connection is rejected.

C6a. The method of embodiment C6, wherein the first message is one of the following: an RRCReject message, or an RRCRelease message that also indicates the UE’s connection with the RAN is released or suspended. C6b. The method of embodiment C6a, where the first message explicitly or implicitly indicates that the UE should retain the stored QoE-related information after UE’s connection with the RAN is released or suspended.

DI. A user equipment (UE) configured to perform quality-of-experience (QoE) measurements in a radio access network (RAN), the UE comprising: communication interface circuitry configured to communicate with RAN nodes; and processing circuitry operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to any of the methods of embodiments A1-A8.

D2. A user equipment (UE) configured to perform quality-of-experience (QoE) measurements in a radio access network (RAN), the UE being further configured to perform operations corresponding to any of the methods of embodiments A1-A8.

D3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) configured to perform quality-of-experience (QoE) measurements in a radio access network (RAN), configure the UE to perform operations corresponding to any of the methods of embodiments A1-A8.

D4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) configured to perform quality-of- experience (QoE) measurements in a radio access network (RAN), configure the UE to perform operations corresponding to any of the methods of embodiments A1-A8.

El . A target radio access network (RAN) node configured to manage quality-of-experience (QoE) measurements by user equipment (UEs) in the RAN, the RAN node comprising: communication interface circuitry configured to communicate with UEs and with a source RAN node; and processing circuitry operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to any of the methods of embodiments B1-B9. E2. A target radio access network (RAN) node configured to manage quality-of-experience (QoE) measurements by user equipment (UEs) in the RAN, the target RAN node being further configured to perform operations corresponding to any of the methods of embodiments B1-B9.

E3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a target radio access network (RAN) node configured to manage quality-of-experience (QoE) measurements by user equipment (UEs) in the RAN, configure the target RAN node to perform operations corresponding to any of the methods of embodiments B1-B9.

E4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a target radio access network (RAN) node configured to manage quality-of-experience (QoE) measurements by user equipment (UEs) in the RAN, configure the target RAN node to perform operations corresponding to any of the methods of embodiments B1-B9.

Fl. A source radio access network (RAN) node configured to manage quality-of-experience (QoE) measurements by user equipment (UEs) in the RAN, the RAN node comprising: communication interface circuitry configured to communicate with UEs and with a source RAN node; and processing circuitry operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to any of the methods of embodiments Cl-C6b.

F2. A source radio access network (RAN) node configured to manage quality-of-experience (QoE) measurements by user equipment (UEs) in the RAN, the source RAN node being further configured to perform operations corresponding to any of the methods of embodiments Cl-C6b.

F3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a source radio access network (RAN) node configured to manage quality-of-experience (QoE) measurements by user equipment (UEs) in the RAN, configure the source RAN node to perform operations corresponding to any of the methods of embodiments Cl-C6b. F4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a source radio access network (RAN) node configured to manage quality-of-experience (QoE) measurements by user equipment (UEs) in the RAN, configure the source RAN node to perform operations corresponding to any of the methods of embodiments Cl-C6b.

Claims

1. A method for a user equipment, UE, configured to perform quality-of-experience, QoE, measurements in a radio access network, RAN, the method comprising: obtaining and storing (1020) QoE-related information; subsequently connecting (1030) to a first cell served by a first RAN node; while at least a portion of the stored QoE-related information has not been sent to the first RAN node, performing (1050) a mobility operation from the first cell to a second cell served by a second RAN node; and sending (1060), to the second RAN node, an indication of QoE-related information available to be fetched from the UE.

2. The method of claim 1 , wherein the QoE-related information includes one or more of the following: one or more network, NW, QoE measurement collection, QMC, configurations maintained by the RAN to facilitate QoE measurements by the UE; and one or more QoE reports based on QoE measurements performed by the UE in accordance with one or more UE QMC configurations.

3. The method of claim 2, wherein obtaining (1020) the QoE-related information includes the following: receiving (1021) the one or more NW QMC configurations from the RAN while in a connected state with respect to the RAN; subsequently transitioning (1022) to a non-connected state with respect to the RAN; and performing (1023) the QoE measurements while in the non-connected state before connecting to the first cell.

4. The method of claim 3, wherein the QoE measurements are performed for one or more applications carried by a broadcast service received by the UE while operating in the nonconnected state.

5. The method of any of claims 3-4, further comprising, while connected to the first cell and before the mobility operation, receiving (1040) from the first RAN node a message indicating support for reception of QoE-related information stored by the UE while in the nonconnected state.

6. The method of any of claims 1-5, further comprising, while connected to the first cell and before the mobility operation, sending (1045) a subset of the QoE-related information to the first RAN node.

7. The method of any of claims 1-5, further comprising, selectively discarding (1035) a subset of the stored QoE-related information, based on priority information associated with the stored QoE-related information.

8. The method of any of claims 1-7, wherein the mobility operation is a handover, and the indication of QoE-related information available to be fetched from the UE is sent to the second RAN node in one of the following messages: a message that indicates UE completion of handover execution to the second cell; or a reconfiguration complete message responsive to a reconfiguration message received from the second RAN node.

9. The method of any of claims 1 -7, wherein: performing (1050) the mobility operation comprises detecting (1052) a radio link failure, RLF, in the source cell and reestablishing the UE’s connection with the RAN in the second cell; and the indication of QoE-related information available to be fetched from the UE is sent to the second RAN node in one of the following messages: a reestablishment complete message that indicates UE completion of connection reestablishment in the second cell; or a reconfiguration complete message responsive to a reconfiguration message received from the second RAN node.

10. The method of any of claims 1-7, wherein: performing (1050) the mobility operation comprises: sending (1053) to the second RAN node a request to resume the UE’s connection with the RAN in the second cell, and receiving (1054) from the second RAN node a first message indicating that the request to resume the UE’s connection is rejected; the indication of QoE-related information available to be fetched from the UE is included in a second message sent after receiving the first message.

11. The method of claim 10, wherein the first message is an RRCSetup message that also indicates a new connection for the UE will be set up in the second cell, and the second message is an RRCSetupComplete message indicating UE completion of connection setup in the second cell.

12. The method of claim 10, wherein: the first message is one of the following: an RRCReject message, or an RRCRelease message that also indicates the UE’s connection with the RAN is released or suspended; and the second message is sent during or after setup of a new connection for the UE in the second cell

13. The method of any of claims 1-12, further comprising: in response to the indication of QoE-related information available to be fetched from the UE, receiving (1070) from the second RAN node a request for the QoE-related information available to be fetched from the UE; and sending (1080) the available QoE-related information to the second RAN node in response to the request.

14. A method for a second radio access network, RAN, node configured to manage quality- of-experience, QoE, measurements by user equipment, UEs, in the RAN, the method comprising: performing or facilitating (1110) a mobility operation for a UE from a first cell served by a first RAN node to a second cell served by the second RAN node; and receiving (1120) from the UE an indication of QoE-related information available to be fetched from the UE, wherein: the QoE-related information was obtained and stored by the UE before the UE connected to the first cell, and at least a portion of the stored QoE-related information was not sent by the UE to the first RAN node before the mobility operation.

15. The method of any of claim 14, wherein: performing or facilitating (1110) the mobility operation comprises: receiving (1111) from the UE a request to resume the UE’s connection with the RAN in the second cell, and sending (1112) to the UE a first message indicating that the request to resume the UE’s connection is rejected; and the indication of QoE-related information available to be fetched from the UE is included in a second message received after sending the first message.

16. The method of any of claims 14-15, further comprising: in response to the indication of QoE-related information available to be fetched from the UE, sending (1130) to the UE a request for the QoE-related information available to be fetched from the UE; and receiving (1140) the available QoE-related information from the UE in response to the request.

17. User equipment, UE (210, 410, 510, 1312, 1400) configured to perform quality-of- experience, QoE, measurements in a radio access network, RAN (199, 1304), the UE comprising: communication interface circuitry (1412) configured to communicate with RAN nodes (100, 150, 220, 420, 520, 1310, 1500, 1602); and processing circuitry (1402) operatively coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to: obtain and store QoE-related information; subsequently connect to a first cell served by a first RAN node; while at least a portion of the stored QoE-related information has not been sent to the first RAN node, perform a mobility operation from the first cell to a second cell served by a second RAN node; and send, to the second RAN node, an indication of QoE-related information available to be fetched from the UE.

18. The UE of claim 17, wherein the processing circuitry and the communication interface circuitry are further configured to perform operations corresponding to any of the methods of claims 2-13.

19. User equipment, UE (210, 410, 510, 1312, 1400) configured to perform quality-of- experience, QoE, measurements in a radio access network, RAN (199, 1304), the UE being further configured to: obtain and store QoE-related information; subsequently connect to a first cell served by a first RAN node (100, 150, 220, 420, 520, 1310, 1500, 1602); while at least a portion of the stored QoE-related information has not been sent to the first RAN node, perform a mobility operation from the first cell to a second cell served by a second RAN node (100, 150, 220, 420, 520, 1310, 1500, 1602); and send, to the second RAN node, an indication of QoE-related information available to be fetched from the UE.

20. The UE of claim 19, being further configured to perform operations corresponding to any of the methods of claims 2-13.

21. Non-transitory, computer-readable medium (1410) storing computer-executable instructions that, when executed by processing circuitry (1402) of a user equipment, UE (210, 410, 510, 1312, 1400) configured to perform quality-of-experience, QoE, measurements in a radio access network, RAN (199, 1304), configure the UE to perform operations corresponding to any of the methods of claims 1-13.

22. Computer program product (1414) comprising computer-executable instructions that, when executed by processing circuitry (1402) of a user equipment, UE (210, 410, 510, 1312, 1400) configured to perform quality-of-experience, QoE, measurements in a radio access network, RAN (199, 1304), configure the UE to perform operations corresponding to any of the methods of claims 1-13.

23. Second radio access network, RAN, node (100, 150, 220, 420, 520, 1310, 1500, 1602) configured to manage quality-of-experience, QoE, measurements by user equipment, UEs (210, 410, 510, 1312, 1400) in the RAN (199, 1304), the second RAN node comprising: communication interface circuitry (1506, 1604) configured to communicate with UEs and with a first RAN node (100, 150, 220, 420, 520, 1310, 1500, 1602); and processing circuitry (1502, 1604) operatively coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to: perform or facilitate a mobility operation for a UE from a first cell served by the first RAN node to a second cell served by the second RAN node; and receive from the UE an indication of QoE-related information available to be fetched from the UE, wherein: the QoE-related information was obtained and stored by the UE before the connecting to the first cell, and at least a portion of the stored QoE-related information was not sent by the UE to the first RAN node before the mobility operation.

24. The second RAN node of claim 23, wherein the processing circuitry and the communication interface circuitry are further configured to perform operations corresponding to any of the methods of claims 15-16.

25. Second radio access network, RAN, node (100, 150, 220, 420, 520, 1310, 1500, 1602) configured to manage quality-of-experience, QoE, measurements by user equipment, UEs (210, 410, 510, 1312, 1400) in the RAN (199, 1304), the second RAN node being further configured to: perform or facilitate a mobility operation for a UE from a first cell served by a first RAN node (100, 150, 220, 420, 520, 1310, 1500, 1602) to a second cell served by the second RAN node; and receive from the UE an indication of QoE-related information available to be fetched from the UE, wherein: the QoE-related information was obtained and stored by the UE before the connecting to the first cell, and at least a portion of the stored QoE-related information was not sent by the UE to the first RAN node before the mobility operation.

26. The second RAN node of claim 25, being further configured to perform operations corresponding to any of the methods of claims 15-16.

27. Non-transitory, computer-readable medium (1504, 1604) storing computer-executable instructions that, when executed by processing circuitry (1502, 1604) of a second radio access network, RAN, node (100, 150, 220, 420, 520, 1310, 1500, 1602) configured to manage quality- of-experience, QoE, measurements by user equipment, UEs (210, 410, 510, 1312, 1400) in the RAN (199, 1304), configure the second RAN node to perform operations corresponding to any of the methods of claims 14-16.

28. Computer program product (1504a, 1604a) comprising computer-executable instructions that, when executed by processing circuitry (1502, 1604) of a second radio access network,

RAN, node (100, 150, 220, 420, 520, 1310, 1500, 1602) configured to manage quality-of- experience, QoE, measurements by user equipment, UEs (210, 410, 510, 1312, 1400) in the RAN (199, 1304), configure the second RAN node to perform operations corresponding to any of the methods of claims 14-16.